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Cauldron Cake

This cauldron cake is made with delicious black cocoa cake layers and has a spooky Jello potion center!! It’s the ultimate Halloween cake!

image of a cauldron cake made with black cocoa frosting and cake layers and a jello potion center

How to Make This Spooky Cauldron Cake

To make sure this cake turns out as amazing as possible, let’s walk through each step together!

I figured it might be helpful to know what tools I use too, so I’ve shared a list below.

Not all of these are mandatory, but they make the process a lot easier. If you don’t have all these things on hand, feel free to improvise and work with what you have.

Step 1: Make the Gradient Jello for the Inside of the Cake

The first step is to make the jello that will be used to make the gradient in the center of the cake!

After making the gelatin mixture, split the mixture between two shallow, wide bowls or cake pans and color one light green and one dark green. Place these in the fridge to chill and set.

This usually takes about an hour but can vary based on the size of the bowls you use.

It can also be made up to a week in advance. If you do make these further in advance, cover the bowls with plastic wrap.

Step 2: Make the Black Cocoa Cake Layers

Next, we make the black cocoa cake layers. Preheat oven to 350°F / 175°C. Line four 7″ or three 8″ pans with parchment rounds, and grease with non-stick baking spray.

I used 7″ pans. You can also use this recipe to make four, 6″ cake layers but the bake time will be a few minutes longer and your cauldron will end up being a bit taller than mine.

Divide the batter evenly between the prepared pans. I like to use a scale to make sure each pan has the same amount of batter and will bake up to be the same height.

image of pouring black velvet cake batter into pans

Bake for 33-35 minutes or until a toothpick comes out with a few moist crumbs.

Let the pans cool for 10 minutes, then run a small offset spatula around the perimeter of the pan to separate the cake from the pan.

Place the cake layers into the freezer for 30 minutes to accelerate the cooling process. Once the layers are fully cooled, carefully flip the pans and remove the layers.

Step 3: Level and Trim the Cake Layers

Use a serrated knife to level the tops of the layers.

image of moist black cocoa cake layers that have been leveled with a serrated knife

Then use a large circle cutter (mine was 4″ in diameter) to remove the center from three of the cake layers. If you are worried about removing too much of the cake, you can just remove the center from two of the layers.

Also, if you don’t have a circle cutter, you can use a small bowl or cup as a guide and cut around it with a small knife.

image of a circle cutter being used to remove the center of a black cocoa cake layer

At this point you can wrap and freeze the cake layers if you’re making them in advance.

Step 4: Make the Buttercream Frosting

While the cake layers bake and cool, make the buttercream frosting.

Mix the frosting on the lowest speed with a paddle attachment once it’s made to push out any excess air.

image of vanilla buttercream being mixed that's smooth

I also like to stir it by hand with a rubber spatula once it’s fully made. This makes the frosting silky smooth and easier to smooth onto your cake.

This frosting can also be made in advance if needed and kept in the fridge for up to a month.

Once the frosting is made, scoop 1/3 cup of frosting into a small bowl and color it yellow with gel food coloring. Use a butter knife or large offset spatula to spread the frosting in a line inside a large piping bag fit with an open star tip (like a Wilton 1M). Cover about 1/3 of the inside of the bag.

In the same bowl, add another 1/3 cup of frosting and color it orange. Spread it inside the piping bag next to the yellow, covering about 1/3 of the inside of the bag.

Repeat this process again but do it with frosting red. Spread it inside the piping bag between the yellow and orange frosting. This will be used to make the flames up the side of the cauldron.

image of red, orange, and yellow buttercream in a frosting bag that will be used to pipe tri-colored swirls on a cake to look like flames

Color the remaining buttercream green with gel food coloring and cover the frosting with plastic wrap to prevent crusting and set aside.

Don’t worry about the black frosting yet – we will transform the green frosting into black frosting once the cake has been stacked and crumb coated.

Step 5: Assembling this Cauldron Cake

Stack and frost the cake layers on a greaseproof cake board or flat plate using a dab of frosting to help stick the first cake layer to the board.

Start with the only full layer, then top it with the cut-out cake layers.

Spread an even layer of green buttercream between each cake layer with a large offset spatula.

image of black cocoa cake layers being stacked with green buttercream

Once the cake layers are stacked, cover the entire cake in a thin layer of green frosting.

Make sure you fully cover the cake layers, including the area in the center where the gelatin potion will be added.

Otherwise, the gelatin mixture can seep into the cake layers before it sets.

image of the inside cut-out section of a cake being frosted with green buttercream

Smooth using an offset spatula and acetate sheet, then chill the cake in the fridge (20 minutes) or freezer (5 minutes) until the frosting is firm to the touch.

While the cake chills, color the remain frosting black by adding in 1/4 cup of black cocoa powder, 1/4 cup of heavy cream, and a generous squirt of black gel food coloring.

Stir until combined and evenly colored. Place the black frosting in a large piping bag and cut a 1 cm opening at the tip of the bag.

Cover the chilled cake with a second, thicker layer of black buttercream. Smooth using an offset spatula and acetate sheet.

image of black buttercream being smoothed onto a cauldron cake with an acetate sheet

Pipe two small handles on the side of the cake, then pipe a lip around the top of the cake to look like the rim of the cauldron.

Use the red, orange, and yellow frosting to pipe flames around the base of the cake.

I accidentally forgot to add the frosting flames until I’d filled the cake with gelatin, but I think it’d be much easier if it’s added during this stage of the process 🙂

Chill the cake again in the fridge (20 minutes) or freezer (5 minutes) until the frosting is firm to the touch.

Step 6: Adding the Gelatin Potion Center

While the cake chills, crumble both pans of chilled green jello with a fork.

image of green gelatin being crumbled up to be added to a cauldron

Next, make the liquid electric green potion gelatin following the recipe card below.

Remove the cake from the fridge and add the crumbled green gelatin into the cut-out center of the cake.

image of jelly crumbles being added into the center of cauldron cake to look like a potion

Add the deep green gelatin first, followed by the lighter green gelatin crumbles.

Carefully pour the bright green gelatin mixture that was just made over the gelatin crumbles inside the cake. Pour until the center of the cake is completely filled with gelatin.

image of lime green gelatin being poured into the center of a cauldron cake

Quickly top the gelatin with gummy eyeballs and green sprinkles before the gelatin fully sets.

image of gummy eyeballs being added to the top of a spooky halloween cauldron cake

Place the cake in the fridge and chill for about 3 hours, or until the gelatin portion is set and firm to the touch. Then cut in and enjoy!

image of a cauldron cake that's been cut open to show it's spooky and cool green gelatin center

While the gelatin potion center is edible, it has a super firm texture and is mostly there for show. I recommend serving up just the cake portion of this cake!

Substitutions & Swaps – Cauldron Cake

Some swaps and substitutions that can be made in this recipe include:

  • All-Purpose Flour– This recipe turns out best with all-purpose flour. However, you can swap in a good gluten free flour blend (like this) if needed. Just be sure to stir the batter longer than normal to help give the cake proper structure, and let the batter sit for about 20 minutes before baking it if you opt to make a gluten free version.
  • Black Cocoa – I love using black cocoa (I order black cocoa on Amazon) because it naturally colors both the cake layers and frosting. If you can’t get black cocoa, you can use dark cocoa powder or Dutch-processed cocoa powder in its place. You can also use regular cocoa powder and add in a bit more gel food coloring.
  • Egg Whites – 5 large eggs can be used in place of the cup of egg whites that this recipe calls for. Or if you have an egg allergy you can try using a vegan egg replacer or flaxseed eggs.
  • Buttermilk – You can also use full fat yogurt, sour cream, whole milk, or an alternative yogurt or milk (almond, soy, oat) if needed.
  • Vegetable Oil – Use any flavorless oil in this recipe.
  • Gel Food Coloring – Gel food coloring is a must! It gives the frosting and gelatin center a vibrant, spooky color. I love using Americolor and Chefmaster, but other brands of gel food coloring should work too. I don’t recommend using liquid food coloring.
  • Unflavored Gelatin – This recipe uses a TON of gelatin. I recommend buying a tub like this! Do not swap in flavored Jello for the unflavored gelatin in this recipe. I have not tested this recipe with agar agar, and I’m not sure it will set firm enough to make this cake design.
image of a cauldron cake slice on a plate showing its black cocoa cake layers and cool jello center

Substitutions & Swaps: Buttercream Frosting

  • Unsalted Butter – If you only have salted butter on hand, you can use it in place of the unsalted butter. Just be sure to omit the salt that this frosting recipe calls for. You can also use vegan butter in its place!
  • Heavy Cream – You can use whole milk or alternative milk (soy, almond, oat) instead of heavy cream or whipping cream. This will thin the frosting out more though, so I recommend using about half the amount the recipe calls for.

Tips for Making the Best Cauldron Cake

  • Ingredients at room temp mix together better! Set out any cold ingredients ahead of time.
  • Properly measure your flour (spoon into the cup measure, then level). Or better yet, use a kitchen scale to measure your dry ingredients.
  • Level your room temperature or thawed cake layers with a serrated knife to make them easier to stack.
  • Chill your cake layers in the freezer for about 20 minutes before assembling the cake. It makes it so much easier to stack and frost them!
  • Thoroughly cover the cutout portion of the cake with buttercream. This will prevent leaks and keep the gelatin potion in place.
image of a cauldron cake made with black cocoa frosting and cake layers and a jello potion center

Making This Halloween Cauldron Cake in Advance and Storage Tips

Make the cake layers in advance and freeze them. It breaks the process up and makes it more approachable.

You can also make the frosting ahead of time or save any leftover frosting. Store it in an airtight container in the fridge for up to a month.

Just be sure to give it a good stir once it thaws to make it nice and smooth again. This cake can last in the fridge for up to 3 days.

image of a cut into cauldron cake that has a spooky gelatin center that's green to look like a potion

Let Me Know What You Think

If you try this cauldron cake recipe, I’d love to hear what you think! Please leave a rating and comment below.

Don’t forget to tag me @chelsweets and use #chelsweets on social media so I can see your amazing creations!

Other Recipes You Might Like:

Yield: 20

Cauldron Cake

image of a cauldron cake made with black cocoa frosting and cake layers and a jello potion center

This cauldron cake is made with delicious black cocoa cake layers and buttercream and has a spooky jello potion center!! It's the ultimate Halloween cake!

Prep Time 30 minutes
Cook Time 33 minutes
Additional Time 3 hours
Total Time 4 hours 3 minutes

Ingredients

Potion Gradient Jello

Black Cocoa Cake Recipe

  • 3 cups granulated sugar (600g)
  • 2 1/4 cups all-purpose flour (280g)
  • 3/4 black cocoa powder (75g)
  • 2 1/2 tsp baking powder (10g)
  • 1 tsp fine salt (6g)
  • 1 cup unsalted butter, room temp (226g)
  • 1 cup egg whites from a carton or 7 large egg whites, room temp (235g)
  • 1 1/2 cups buttermilk, room temp (360g)
  • 2 Tbsp vegetable oil (30g)
  • 2 tsp vanilla extract (8g)

Buttercream Frosting

Potion Gelatin

Cake Decoration

Recommend Tools and Equipment

Instructions

Potion Gradient Jello:

  1. Make the jello that will be used to make the gradient in the center of the cake first! It needs about an hour to set. It can also be made up to a week in advance.
  2. Mix 2 Tbsp of gelatin and 1/2 cup of cold water together in a small bowl until combined. Set aside to let the gelatin absorb the water and bloom (this usually takes about 5 minutes).
  3. In a separate, heat-proof bowl, mix together 1 cup of boiling water and 1/2 cup of sugar. Once the sugar is dissolved, mix in the bloomed gelatin, and whisk until combined. Then mix in 1/2 cup of cold water and 1 tsp of lemon extract (optional).
  4. Split the mixture between two shallow, wide bowls or cake pans and color one light green and one dark green with gel food coloring.
  5. Place these in the fridge to chill and set. This usually takes about an hour but can vary based on the size of the bowl you use. If you do make these further in advance, cover the bowls with plastic wrap.

Black Cocoa Cake Layers:

  1. Next, make the black cocoa cake layers. Preheat oven to 350°F / 175°C. Line four 7" or three 8" pans with parchment rounds, and grease with non-stick baking spray. I used 7" pans. You can also use this recipe to make four, 6" cake layers but the bake time will be a few minutes longer and your cauldron will end up being a bit taller than mine. If you don't have 4 cake pans, the batter can sit at room temperature for a few hours. Bake as many layers at a time as you can at a time.
  2. Mix 3 cups sugar, 2 1/4 cups all purpose flour, 3/4 cup black cocoa powder, 2 1/2 tsp baking powder and 1 tsp salt together in a stand mixer with a paddle attachment or hand mixer until combined.
  3. Mix in 1 cup of unsalted butter into the dry ingredients on a low speed. Continue to mix until no large chunks of butter remain, and the mixture looks like moist sand.
  4. Pour in 1 cup of egg whites and mix on low until combined. Mix in 1 1/2 cups buttermilk in two installments on a low speed.
  5. Add in 2 Tbsp of vegetable oil and 2 tsp of vanilla extract. Mix on a low speed until fully incorporated.
  6. Scrape down the sides of the bowl with a rubber spatula, then beat on a medium speed for about 30 seconds to make sure everything is properly mixed together.
  7. Divide the batter evenly between the prepared pans. I like to use a scale to make sure each pan has the same amount of batter and will bake up to be the same height.
  8. Bake for 33-35 minutes or until a toothpick comes out with a few moist crumbs.
  9. Let the pans cool for 10 minutes, then run a small offset spatula around the perimeter of the pan to separate the cake from the pan.
  10. Place the cake layers into the freezer for 30 minutes to accelerate the cooling process. Once the layers are fully cooled, carefully flip the pans and remove the layers.
  11. Use a serrated knife to level the tops of the layers, then use a large circle cutter (mine was 4" in diameter) to remove the center from three of the cake layers. If you're worried about removing too much of the cake, you can just remove the center from two of the layers. Also, if you don't have a circle cutter, you can use a small bowl or cup as a guide and cut around it with a small knife.
  12. At this point you can wrap and freeze the cake layers if you're making them in advance.
  13. If you make these cake layers in advance and freeze them, let them thaw for about 20 minutes before assembling this cake. The cake layers should still be slightly cold to the touch, which will make it easier to assemble your cake.

Buttercream Frosting:

  1. While the cake layers bake and cool, make the buttercream frosting.
  2. Beat 2 cups of unsalted butter on a medium speed for 30 seconds with a paddle attachment until smooth.
  3. Mix in 1 Tbsp of vanilla extract and 1/2 tsp salt on a low speed.
  4. Then gradually mix in 7 cups of powdered sugar and 1/4 cup of heavy cream on a low speed.
  5. Continue to mix on a low speed for a few minutes until the desired consistency is reached. 
  6. If the frosting seems too thick, add in additional cream (1 Tbsp at a time). If the frosting is too thin, add in more powdered sugar (quarter of a cup at a time).
  7. Scoop 1/3 cup of frosting into a small bowl and color it yellow with gel food coloring. Use a butter knife or large offset spatula to spread the frosting in a line inside a large piping bag fit with an open star tip (like a Wilton 1M). Cover about 1/3 of the inside of the bag.
  8. In the same bowl, add another 1/3 cup of frosting and color it orange. Spread it inside the piping bag next to the yellow, covering about 1/3 of the inside of the bag.
  9. Repeat step 8 but make the frosting red. Spread it inside the piping bag between the yellow and orange frosting. This will be used to make the flames up the side of the cauldron.
  10. Color the remaining buttercream green with gel food coloring and cover the frosting with plastic wrap to prevent crusting and set aside. Don't worry about the black frosting yet - we will transform the green frosting into black frosting once the cake has been stacked and crumb coated.

Assembling This Cauldron Cake:

  1. Stack and frost the cake layers on a greaseproof cake board or flat plate using a dab of green frosting to help stick the first cake layer to the board. Start with the only full layer, then top it with the cut-out cake layers.
  2. Spread an even layer of green buttercream between each cake layer with a large offset spatula.
  3. Once the cake layers are stacked, cover the entire cake in a thin layer of green frosting. Make sure you fully cover the cake layers, including the area in the center where the gelatin potion will be added. Otherwise, the gelatin mixture can seep into the cake layers before it sets.
  4. Smooth using an offset spatula and acetate sheet, then chill the cake in the fridge (20 minutes) or freezer (5 minutes) until the frosting is firm to the touch.
  5. While the cake chills, color the remain frosting black by adding in 1/4 cup of black cocoa powder, 1/4 cup of heavy cream, and a generous squirt of black gel food coloring. Stir until combined and evenly colored. Place the black frosting in a large piping bag and cut a 1 cm opening at the tip of the bag.
  6. Cover the chilled cake with a second, thicker layer of black buttercream. Smooth using an offset spatula and acetate sheet. Pipe two small handles on the side of the cake, then pipe a lip around the top of the cake to look like the rim of the cauldron.
  7. Use the red, orange, and yellow frosting to pipe flames around the base of the cake.
  8. Chill the cake again in the fridge (20 minutes) or freezer (5 minutes) until the frosting is firm to the touch.

Adding the Gelatin Potion Center to This Cauldron Cake:

  1. While the cake chills, crumble both pans of the chilled green jello that we made earlier with a fork.
  2. Combine 1/2 cup of powdered gelatin and 3/4 cup of cold water in a small mixing bowl. Set aside to let the gelatin absorb the water and bloom (this usually takes about 5 minutes).
  3. Add 3/4 cup of boiling water and 1 cup of sugar into a large mixing bowl and whisk together until combined. Add the bloomed gelatin, 1 tsp lemon extract (optional), and a squirt of electric green gel food coloring. Mix until the gelatin is completely dissolved and the mixture is a bright shade of green.
  4. Remove the cake from the fridge and add the crumbled green gelatin into the cut-out area. Add the deep green gelatin first, followed by the lighter green gelatin crumbles.
  5. Carefully pour the liquid, bright green gelatin mixture that was just made over the gelatin crumbles inside the cake. Pour until the center of the cake is completely filled with gelatin.
  6. Quickly top the gelatin with gummy eyeballs and green sprinkles before the gelatin starts to set.
  7. Then place the cake in the fridge and chill for about 3 hours, or until the gelatin center is set and firm to the touch.
  8. While the gelatin potion center is edible, it has a super firm texture and is mostly there for show. I recommend eating just the cake portion of this cake!

Notes

Ingredient Swaps & Substitutions

For a list of ingredient swaps and substitutions that can be made in this recipe, please refer to the section above titled "Swaps and Substitutions."

Tips for Making the Best Cauldron Layer Cake

  • Ingredients at room temp mix together better! Set out any cold ingredients ahead of time.
  • Properly measure your flour (spoon into the cup measure, then level). Or better yet, use a kitchen scale to measure your dry ingredients.
  • Bang your cake pans on the counter before putting it in the oven. This brings any big air bubbles that are trapped in the batter to the surface.
  • Level your room temperature or thawed cake layers with a serrated knife to make them easier to stack.
  • Chill your cake layers in the freezer for about 20 minutes before trimming them and assembling the cake. It makes the process so much easier!
  • Thoroughly cover the cutout portion of the cake with buttercream. This will prevent leaks and keep the gelatin potion in place.

Making This Cauldron Cake in Advance & Storage Tips

Make your cake layers in advance and freeze them. It breaks the process up and makes it more approachable.

Make your frosting ahead of time too or save any leftover frosting! It can be stored in an airtight container in the fridge for up to a month, or in the freezer for up to 3 months. Be sure to give it a good stir once it thaws to get the consistency nice and smooth again.

A frosted cake can last in the fridge for up to 3 days. The buttercream locks in all the moisture, keeping the cake fresh and delicious!

Nutrition Information

Yield

20

Serving Size

1

Amount Per Serving Calories 745Total Fat 33gSaturated Fat 19gTrans Fat 0gUnsaturated Fat 12gCholesterol 87mgSodium 358mgCarbohydrates 103gFiber 1gSugar 89gProtein 12g

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