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Black and White Cake

Black and White Cake is a fancy dessert that's easier to make than it looks. And it's totally delicious!

Course Dessert
Cuisine American
Prep Time 45 minutes
Cook Time 42 minutes
Total Time 1 hour 27 minutes
Servings 10
Author Kelsie

Ingredients

Cake layers

  • 1 (16.25-ounce) box white cake mix*
  • 1 cup all-purpose flour
  • 1 cup granulated sugar
  • 1 cup full-fat sour cream
  • 1 cup water
  • 5 large egg whites
  • 1/2 cup vegetable oil
  • 1 teaspoon vanilla extract clear if you have it

Chocolate filling

  • 3/4 cup heavy cream
  • 5 1/2 ounces dark chocolate finely chopped
  • 3 tablespoons powdered sugar

White chocolate buttercream

  • 4 ounces white chocolate finely chopped
  • 1 1/2 cups unsalted butter at room temperature
  • 4 1/2 to 5 cups powdered sugar
  • 3 to 6 tablespoons milk or cream
  • 1 teaspoon vanilla extract
  • 1/4 teaspoon salt
  • chocolate curls for decorating if desired

Instructions

Cake layers

  1. Preheat the oven to 350 degrees. Spray 2 8-inch round cake pans with cooking spray. Line the bottom of the pans with parchment paper, then spray the paper with more cooking spray. Set pans aside.
  2. Combine the cake mix, flour, sugar, sour cream, water, egg whites, vegetable oil, and vanilla in a large mixing bowl.
  3. Beat with an electric mixer on medium speed for about 2 minutes—the batter should be very smooth and well mixed. Scrape down the sides and bottom of the bowl and mix a few seconds more.
  4. Pour into the prepared cake pans and bake 42 to 48 minutes, until a cake tester inserted into the center of the cake comes out clean.
  5. Cool for 20 minutes in pans, then run a knife around the edge of the pans and carefully invert onto a wire rack to cool completely before assembling your cake. (Once the layers are cool you can wrap then tightly with plastic wrap and store at room temperature for a day or two.)

Chocolate filling

  1. While your cake layers are cooling, make the filling. Place heavy cream in a small saucepan set over medium heat and heat until the cream just starts to steam.
  2. Place chocolate in a medium heat-proof mixing bowl and pour the hot cream over it. Allow to sit for 4 minutes, then whisk until chocolate is melted and mixture is smooth. Cool to room temperature.
  3. Beat the cooled ganache with an electric mixer set to low; gradually increase the speed to medium-high.
  4. Add the powdered sugar and continue beating until the ganache becomes light and fluffy; this will take several minutes. (If the ganache doesn’t thicken as much as you’d like, refrigerate it for a few minutes until it’s spreadable.) Set aside while you make the buttercream.

White chocolate buttercream

  1. Place the chocolate in a microwave-safe bowl and heat on 50% power in 15-second intervals, stirring after each interval, until chocolate is melted and smooth. (It will take about a minute and a half.) Set aside to cool.
  2. Place the butter in a large mixing bowl and beat with an electric mixer set to medium speed until very creamy. Turn mixer to low and beat in 4 1/2 cups of the powdered sugar, 3 tablespoons of the milk, and the vanilla and salt until well combined.

  3. Add the cooled white chocolate and mix on low until incorporated. Turn mixer to medium and beat until very smoothl. Add additional powdered sugar to thicken frosting or additional milk to thin it out to a spreadable consistency.

Assembly

  1. Trim your cake layers with a long serrated knife if they’ve domed. Use the same long serrated knife to split each layer in half horizontally.
  2. Place one cake layer on a cake stand or cardboard cake circle. Transfer about 1 1/2 cups of the white chocolate buttercream to a pastry bag fitted with a large round tip.
  3. Pipe a circle (or twof frosting around the perimeter of your cake and use a small offset spatula to spread half of the chocolate filling into an even layer inside the circle.
  4. Top with a second cake layer and spread a layer of white chocolate buttercream over that. Top with a third cake layer and repeat the filling process, using the remaining chocolate filling. Top with the last cake layer and frost the cake with the remaining buttercream.
  5. Decorate the cake as desired and serve. Uneaten cake can be stored in the fridge, loosely covered with plastic wrap, for up to 3 days, or tightly wrapped in the freezer for up to 3 months.

Recipe Notes

  • *I used Betty Crocker
  • For tips on dividing this cake up over several days, please see the body of this post
  • For tips on making chocolate curls for garnish, please see the body of this post
  • Because this is a fairly long recipe, I recommend reading the recipe through once before you start baking