White Chocolate Mousse Cake

White Chocolate Mousse Cake
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  • 70 mins
  • Prep: 45 mins,
  • Cook: 25 mins
  • Yield: 16 servings

The combination of cake, filling, and frosting is just sublime. This gorgeous cake is very easy to make, especially if you divide it into steps on different days. Bake the cake one day and reserve it (or freeze it up to 3 months). Then make the mousse and frosting and assemble the cake.

This is the perfect cake for any celebration, especially birthdays. It takes some time to make, but the results are so worth it. Anyone who loves white cake will think that this is the perfect dessert. 

What You'll Need

  • 1 (18 ounce) package two layer white cake mix
  • 1-1/4 cups water
  • 1/3 cup oil
  • 3 egg whites
  • 2 tablespoons whipping cream
  • 1/2 cup white chocolate chips
  • 1/2 cup mascarpone cheese
  • 1 teaspoon vanilla
  • 1/2 cup heavy whipping cream
  • 2 tablespoons powdered sugar
  • 1/2 cup butter, softened
  • 2 cups powdered sugar
  • 1 teaspoon vanilla
  • 2 to 3 tablespoons milk
  • 1 cup white chocolate chips
  • 2 to 3 tablespoons milk

How to Make It

Preheat the oven to 350 degrees. Spray two 9" round layer cake pans with nonstick baking spray containing flour and set aside.

In a large bowl, combine the cake mix, 1-1/4 cups water, oil, and egg whites, and blend. Beat two minutes at high speed.

Pour the batter into the prepared pans and bake at 350 degrees for 25-35 minutes until toothpick inserted in cake comes out clean. Cool on wire rack for 15 minutes, then remove the cakes from the pans and cool completely on a wire rack.

For the filling, in a small bowl combine 2 tablespoons whipping cream with 1/2 cup white chocolate chips. Microwave on 50% power, stirring occasionally, for 2 to 4 minutes until chips are melted and mixture is smooth. In another small bowl, beat the mascarpone cheese and 1 teaspoon vanilla until smooth. Beat in the melted white chocolate chip mixture until smooth. Then beat 1/2 cup heavy cream with 2 tablespoons sugar until thick in yet another small bowl; fold into mascarpone mixture; refrigerate until you're ready to assemble the cake.

For the frosting, beat together 1/2 cup softened butter, 2 cups powdered sugar, 1 teaspoon vanilla, and enough milk for a smooth spreading consistency. Set aside.

To assemble the cake, place one cake layer upside down on a serving plate. Top with all of the white chocolate filling.

Place the remaining cake layer, right side up, on top of the filling. Frost the top and sides of the cake with the frosting. Store the cake, covered, in the refrigerator. Bring it out of the fridge 20 minutes before serving.