The combination of cake, filling, and frosting in this recipe for white chocolate mousse cake is just sublime.
This gorgeous cake takes some time to prepare but it is very easy (because you start with a mix), especially if you divide it into steps and make it over the course of a few days. Bake the cake one day and reserve it (or freeze it up to 3 months). Then make the mousse and frosting another day, and assemble it the same day or the next day.
Perfect for any celebration, it is especially appropriate for birthdays. Anyone who loves white cake will think this is the perfect dessert.
- For the Cake:
- 1 (18-ounce) package white cake mix
- 1 1/4 cups water
- 1/3 cup oil
- 3 large egg whites
- For the Filling:
- 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 confectioners' sugar
- For the Frosting:
- 4 ounces butter (room-temperature)
- 2 cups confectioners' sugar
- 1 teaspoon vanilla
- 2 to 3 tablespoons milk
Make the Cake
Heat the oven to 350 F. Spray two 9-inch round cake pans with nonstick baking spray that contains flour and set aside.
In a large bowl, combine the cake mix, water, oil, and egg whites. Beat 2 minutes at high speed.
Pour the batter into the prepared pans and bake for 25 to 35 minutes or until a 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.
Make the Filling
In a small heatproof bowl, combine 2 tablespoons whipping cream with 1/2 cup white chocolate chips. Microwave on 50 percent power, stirring occasionally, for 2 to 4 minutes or until the chips are melted and the mixture is smooth. Set aside.
In another small bowl, beat the mascarpone cheese and 1 teaspoon vanilla until smooth. Beat in the reserved melted white chocolate chip mixture until smooth.
In another separate small bowl, beat 1/2 cup heavy cream with 2 tablespoons confectioners' sugar until thick. Fold into the mascarpone mixture and refrigerate until you're ready to assemble the cake.
Make the Frosting and Assemble
For the frosting, beat together butter, 2 cups confectioners' 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.