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Chocolate Peanut Butter Cup Galaxy Cake

This stunning Chocolate Peanut Butter Cup Galaxy Cake combines rich chocolate and creamy peanut butter in a visually striking galaxy design, making it perfect for any celebration.
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Prep Time 20 minutes
Cook Time 35 minutes
Total Time 55 minutes
Servings: 12 servings
Course: Cake, Dessert
Cuisine: American, Baking
Calories: 450
Ingredients Method Notes

Ingredients
  

For the Cake
  • 2 cups all-purpose flour
  • 2 cups granulated sugar
  • ¾ cup unsweetened cocoa powder
  • 1 ½ teaspoons baking powder
  • 1 ½ teaspoons baking soda
  • 1 teaspoon salt
  • 2 large eggs
  • 1 cup whole milk
  • ½ cup vegetable oil
  • 2 teaspoons vanilla extract
  • 1 cup boiling water
For the Peanut Butter Frosting
  • 1 cup creamy peanut butter
  • ½ cup unsalted butter, softened
  • 4 cups powdered sugar
  • ½ cup heavy cream
For the Galaxy Decoration
  • 1 cup chocolate ganache (melted chocolate and heavy cream)
  • Edible glitter and food colors (blue, purple, and pink)
  • Peanut butter cups for garnish

Method
 

Preparation
  1. Preheat your oven to 350°F (175°C). Grease and flour three 9-inch round cake pans.
  2. In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
  3. Add the eggs, milk, oil, and vanilla to the dry ingredients. Mix until just combined. Stir in the boiling water.
  4. Divide the batter evenly among the prepared cake pans and bake for about 30-35 minutes, or until a toothpick comes out clean.
  5. Allow the cakes to cool for about 10 minutes in the pans before transferring to wire racks to cool completely.
Frosting
  1. In a mixing bowl, beat the peanut butter and softened butter together until smooth. Gradually add the powdered sugar and heavy cream, mixing until spreadable.
Assembly
  1. Layer the cake: Place one layer on a cake stand, frost the top with peanut butter frosting, add the second layer and repeat.
  2. Frost the top and sides of the final layer of cake.
  3. Drizzle chocolate ganache over the top, letting it cascade down the sides. Use food coloring to create swirls, and finish with edible glitter and peanut butter cups.

Notes

You can bake the cake layers a day ahead; store tightly wrapped in plastic at room temperature. Let the cake sit for about 30 minutes after frosting for better flavor.