Spilled Potion Cake

It’s September, which means it’s officially spooky season! To kick off the holiday right, I made a devil’s food cake with pistachio buttercream, decorated to look like a spilling cauldron of a suspicious potion.

It’s no secret in my house that I’m a klutz. I deny it all the time, but the evidence surrounds me constantly. I’m trying to come to terms with it, though, which is probably why I made this cake. Call it a desperate affirmation for the clumsy — you can ruin everything and it still be fabulous!

This cake is made of four layers of devil’s food cake tinted with black food coloring and dark cocoa. I would have loved for the cake to come out a deep, dark black, but I like the contrast between the fondant and the inside crumb and didn’t want to overdo it on the coloring. There’s a fine line between perfectly tinted coloring and chemical-tasting coloring. 

Between the layers, I dolloped generous portions of a neon green pistachio frosting. This is the real showstopper of the cake. Without it, this is really just a chocolate cake. The pistachio frosting is made with packages of instant pudding mix that have been sifted to remove the chunks of nuts. This does give the frosting the littlest bit of a grainy texture. I’ve already started playing with ideas of dissolving the powder in milk first and then compensating for that moisture with more powdered sugar, but I don’t have the ratios figured out just yet.

Decorating the cake was probably the most fun I’ve had with a cake in a while. There was no pressure, and messing up was encouraged. I covered the entire cake with black fondant, which meant I didn’t have to stress over getting perfectly smooth frosting. 

To keep the cauldron positioned snuggly on top, I determined where I planned to put it before I covered the cake in ganache. I made small marks around where the rim meets the fondant and cut a little slit. I nestled the cauldron into the fondant to make sure it fit and I still liked its positioning. This also helped give the cauldron realism, making it more believable that it had spilled since it was resting in a dumping position.

The oozing green potion helped secure the cauldron fully. I made sure there was a good puddle under the cauldron to act like a glue. I squeezed drops all around the sides of the cake, making sure to leave enough to fill the top and put some inside the cauldron. What I was left with was a delicious and whimsical Halloween cake.

For the Cake


1 box devil’s food cake mix (Duncan Hines)

1 cup flour

2 tablespoons dark cocoa

1 cup sugar

1 pinch of salt

3 large eggs

1 cup cold water

1 cup sour cream

3-4 drops black gel food coloring


  1. Preheat the oven to 325 degrees. In a large bowl, whisk together dry ingredients making sure to break up and large clumps of mix, and then set aside.
  2. In a separate bowl, combine water, eggs, sour cream, and food coloring. Mix well. Slowly add wet mixture to dry mixture while beating on medium speed with either a hand mixer or stand mixer.
  3. Once well-combined, divide evenly into 6-inch pans, about 2 cups in each. 
  4. Bake from 20-30 minutes, or until you can insert a toothpick into the center of the cakes and it comes out cleanly.

For the Buttercream


2 cups unsalted butter, softened

2 packets of instant pistachio pudding, sifted

4 to 5 cups powdered sugar

1 tablespoon almond extract

Milk or heavy cream, optional

2-3 drops neon green gel food coloring


Fit a mixer the whisk attachment and mix together the butter, pistachio pudding mix, and powdered sugar, one cup at a time. Begin on low speed until crumbly, and then increase to high and beat for 3 minutes.

Add almond extract and beat again for another minute. If the buttercream is too stiff, add milk or heavy cream 1 tablespoon at a time until the mixture is spreading consistency. Beat until light and fluffy.

Store loosely covered at room temperature.

For the Neon Green Ganache


1 cup white candy melts, finely chopped

1/3 cup heavy cream

2-3 drops neon green gel food coloring


  1. Combine the finely chopped candy melts and heavy cream in a microwave-safe bowl. Stir so that the chocolate is coated with the heavy cream. 
  2. Heat for one minute at 100% power and let stand for one minute. Add food coloring and whisk together until smooth. 
  3. Cover the bowl with plastic wrap close to the surface of the ganache to prevent a skin from forming. Place in the refrigerator overnight to set and whisk vigorously before using.

*Set time is necessary to get the right consistency. If you don’t let it set long enough, the ganache will be thin and runny.

Making the Cake

  1. Trim and level all devil’s food cake rounds to make them even. Optional, coat with simple syrup and let soak in the fridge for a few minutes.
  2. On a cake board, put a dollop of frosting to hold the bottom layer in place. Place the first cake round and top with 1/2 cup buttercream frosting. 
  3. Put another cake layer on top and cover with buttercream. Repeat this process until all layers are stacked. 
  4. Crumb coat the cake and let chill in the fridge for at least 30 minutes.
  5. Roll out the black fondant to be larger than the size of your cake.
  6. Bring out the cake and frost fully.
  7. Drape the black fondant over the cake, making sure to leave allowances all around. Smooth and trim excess fondant.
  8. Transfer the lime green ganache to a squeeze bottle. Start by creating the drips over the sides of the cake, alternating their lengths and thicknesses. The longer you squeeze the bottle, the further down the drips will go.
  9. Fill in the top of the cake with pink ganache and spread evenly with an offset spatula. 
  10. Place a small plastic cauldron on the top of the cake. Squeeze some ganache into the cauldron to give the appearance of the potion spilling out

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s