Here’s a cake that delivers on taste and is great for any Halloween occasion. Well I think you’ll dig this masterpiece. Devils food cake with an electric green buttercream and a simple slime green ganache that makes everything from a Halloween party to a night of scary movies more festive.
- Devils Food Cake box mix (Or if you have your own tried and true chocolate cake recipe)
- 1 1/2 cups of room temperature butter
- 3/4 cup of cocoa Powder
- 4 cups of powdered Sugar
- White Chocolate Chips
- Heavy Cream
- 2 tsp of pure vanilla extract
- Black food coloring/gel
- Electric green food coloring
Equipment: Stand up mixer, rubber spatula, 3 6in round cake pans, and a rotating cake stand if you have one.

Before we go any further, I have to say I am not a baker by any means and my friend Leigh is responsible for making this cake look and taste amazing. With that being said anyone can make this cake. You don’t have to be an experienced baker on the Food Network to pull this together.
First up preheat your oven to 325°. Prepare the cake based on your recipe or by the instructions on the back of the cake box. (There is no shame in box cake for this. Make your life easy here. We won’t tell anyone it’s a box cake!)
GREASE YOUR CAKE PANS!
Once you have the cake prepared, add in your black food coloring. Mine was more charcoal in color, but trust me it will be black when it comes out of the oven. Thoroughly mix in the color and distribute the batter evenly into the three round cakes pans. Bake at 325° for 30 minutes.
While the cake bakes, we will make the buttercream icing for both inside the cake and outside. Break out the stand mixer and with the whisk tool, whisk the butter and powdered sugar till it fluffs. Give it about 5 minutes of whisking before it reaches the right consistency. Turn off the mixer and add your vanilla, cocoa and a pinch of salt. blend on low for about 30 seconds and then add 4 tablespoons of heavy cream into the mix one tablespoon at a time. Scrape the bowl down and finish mixing.
Once it’s together, separate the buttercream into two bowls. Add your black food coloring into one bowl and your electric green color into the other. Mix the color completely by whisking for about 3-5 minutes more to get a more fluffy buttercream. You may want the stand mixer to do the heavy lifting…or heavy whisking.
Now that the cakes are done, pull them out and let them cool on a wire rack till they are cool to add frosting. Once they are cooled, slap the green buttercream on the cake evenly and layer the cake up.
Now that we have our 3 layer cake together, it’s time to add a crumb coat. A crumb coat is a thin layer of frosting on the outside of the cake that will basically become a dam and seals in stray crumbs. Take a very small amount of the black buttercream and go around the outside of the cake. When you achieved this status, we want to freeze the cake for about 10-15 minutes so it sets up.
As the cake sets up in the freezer, let’s make some green slime ganache! Take a cup of your white chocolate chips and microwave them for about a minute to soften them. In a saucepan, heat up 1/2 cup of heavy cream till it begins to bubble. Don’t boil. Pour the heavy cream over the chocolate chips and whisk together till it’s smooth. Add the electric green coloring till you get the color you’re looking for. Let the ganache cool for 20 minutes till it’s room temperature.

Pull the cake out of the freezer and use the rest of the black buttercream to evenly frost the cake. We used a fancy tool to get a fun even looking buttercream layers.
Cool the cake down again so the frosting is cool enough for you to drizzle the ganache over the cake. Definitely make sure your ganache has cooled down enough. No one wants a melted cake! Next drizzle and drip your slime over the top of the cake starting in the middle and working your way to the edges to drip over. There is no science to this. You’re the boss here. Get creative!
Refrigerate the cake and when you’re ready to cut and serve, use a heated knife to help get a clean cut into the cake. Presentation is key! Now you’re ready for movie night or your party guests can indulge in this devilishly slimed cake concoction. Enjoy!
