Cauldron Cake

5 from 4 ratings

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 Time30

Cook Time33

Additional Time3

Total Time4 3

Course: Cakes

Cuisine: American

Servings: 20

Calories: 745kcal

Author: Chelsey White

Ingredients

Potion Gradient Jello

2 Tbsp powdered gelatin 18g, bloomed in 1/2 cup cold water (120g)
1 cup boiling water 240g
1/2 cup granulated sugar 100g
1/2 cup cold water 120g
1 tsp lemon extract, optional 4g
Leaf green gel food coloring

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 temperature 226g
1 cup carton egg whites or 7 large egg whites, room temperature 235g
1 1/2 cups buttermilk, room temperature 360g
2 Tbsp vegetable or canola oil 30g
2 tsp vanilla extract or vanilla bean paste 8g

Buttercream Frosting

2 cups unsalted butter, room temperature 452g
1 Tbsp vanilla extract or vanilla bean paste 12g
1/2 tsp fine salt 3g
7 cups powdered sugar 875g
1/4 cup heavy whipping cream, room temperature 60g
Black, green, red, orange and yellow gel food coloring
1/4 cup black cocoa powder 25g + 1/4 cup additional heavy cream (60g)

Potion Gelatin

1/2 cup powdered gelatin 75g, bloomed in 3/4 cups cold water (180g)
3/4 cup boiling water 180g
1 cup granulated sugar 200g
1 tsp lemon extract, optional 4g
Lime green gel food coloring

Cake Decoration

Recommend Tools and Equipment

Electric Hand Mixer or Stand Mixer Fit w/ Paddle Attachment
4, 7- inch Cake Pans
4- Inch Circle Cutter
Spinning Cake Stand
8- inch Cake Board
Offset Spatula
1 Large Piping Bag
Open Star Piping Tip like a Wilton 1M
Acetate sheet .007" thickness

Instructions

Potion Gradient Jello:

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.
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).
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).
Split the mixture between two shallow, wide bowls or cake pans and color one light green and one dark green with gel food coloring.
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:

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.
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.
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.
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.
Add in 2 Tbsp of vegetable oil and 2 tsp of vanilla extract. Mix on a low speed until fully incorporated.
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.
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.
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.
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.
At this point you can wrap and freeze the cake layers if you're making them in advance.
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:

While the cake layers bake and cool, make the buttercream frosting.
Beat 2 cups of unsalted butter on a medium speed for 30 seconds with a paddle attachment until smooth.
Mix in 1 Tbsp of vanilla extract and 1/2 tsp salt on a low speed.
Then gradually mix in 7 cups of powdered sugar and 1/4 cup of heavy cream on a low speed.
Continue to mix on a low speed for a few minutes until the desired consistency is reached.
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).
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 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.
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:

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

While the cake chills, crumble both pans of the chilled green jello that we made earlier with a fork.
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).
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.
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.
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.
Quickly top the gelatin with gummy eyeballs and green sprinkles before the gelatin starts to set.
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.
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