Go Back
+ servings
Slimy Awesomeness Inside and Out!

Black Magic Buttercream

This ooey gooey Slime Cake is as delicious as it is fun!

Course Dessert
Cuisine American
Keyword Black Magic Buttercream, Slime Cake
Prep Time 15 minutes
Total Time 15 minutes
Servings 8 servings
Author Amanda Rettke


  • 1 1/2 c 340g butter, at room temperature
  • 4 c 500g powdered sugar
  • 3/4 c 94g DARK cocoa powder
  • 4 tbsp. 60ml heavy whipping cream
  • 2 tsp. 10ml McCormick Pure Vanilla Extract
  • pinch table salt
  • 1 teaspoons 5-10ml McCormick Black Food Color


  1. In the bowl of an electric stand mixer fitted with whisk attachment, whisk butter and sugar on medium high speed until very pale and fluffy or about five minutes.

  2. Be sure to stop at least once and scrape the bowl.
  3. With the mixer off, add in dark cocoa powder, vanilla and salt.
  4. Turn mixer on low and blend for about 30 seconds.
  5. One tablespoon at a time add in heavy cream.
  6. Once all cream has been added and mixture is mostly combined, turn off the mixer and scrape down the sides of the bowl.

  7. Add in 1 teaspoon of black food color.
  8. Now turn the mixer onto medium-high to high and whisk for 3-5 minutes or until mixture is lighter and fluffier. (Keep an eye on the buttercream. You may want to add another teaspoon of black food color to reach the desired depth of color.)

  9. The frosting will be shiny and seem to have many large air bubbles throughout and this is exactly what we are going for. (You can smooth those out on the cake if so desired.)