Crunchy Milk Chocolate - Peanut Butter Layer Cake
The genius of this layer cake is its extraordinarily crunchy filling, made with almonds, salted peanuts, creamy peanut butter, chocolate and Rice Krispies. The silky milk-chocolate ganache frosting almost pushes the recipe over the top.
- 2 cups plus 2 tablespoons sugar
- 1 3/4 cups all-purpose flour
- 3/4 cup plus 2 tablespoons unsweetened cocoa powder
- 1 1/2 teaspoons baking powder
- 1 1/2 teaspoons baking soda
- 1 1/2 teaspoons salt
- 2 large eggs
- 1 cup milk
- 1/2 cup vegetable oil
- 1 tablespoon pure vanilla extract
- 3/4 cup plus 2 tablespoons boiling water
- 1/3 cup sliced almonds
- 1/2 cup confectioners’ sugar
- 2 large egg whites
- 1 tablespoon granulated sugar
- 1/2 cup salted roasted peanuts, coarsely chopped
- 1 cup creamy peanut butter
- 2 tablespoons unsalted butter, softened
- 3 ounces milk chocolate, chopped
- 1 cup Rice Krispies
- 1 1/4 pounds milk chocolate, chopped
- 1 3/4 cups plus 2 tablespoons heavy cream, warmed
Make the cake: Preheat the oven to 350°. Butter and flour a 9-by-13-inch cake pan. In a large bowl, whisk the sugar, flour, cocoa, baking powder, baking soda and salt. In a medium bowl, whisk the eggs, milk, oil and vanilla. Whisk the wet ingredients into the dry ingredients. Whisk in the boiling water. Pour the batter (it will be thin) into the prepared pan and bake for about 50 minutes, until a toothpick inserted in the center comes out clean. Let cool.
Invert the cake onto a work surface. Working carefully, slice the cake horizontally. Reduce the oven temperature to 325°.
Make the filling: Trace a 9-by-13-inch rectangle onto a sheet of parchment paper and lay it on a large baking sheet. In a food processor, pulse the almonds with the confectioners’ sugar until they’re finely ground. In a bowl, using an electric mixer, beat the egg whites at medium speed until soft peaks form. Add the granulated sugar and beat until the whites are stiff and glossy, about 2 minutes. Using a rubber spatula, fold in the almond mixture. Spread the meringue on the parchment to fill the rectangle. Sprinkle the chopped peanuts on top. Bake for about 20 minutes, until lightly browned and firm. Let cool.
In a medium bowl set in a saucepan of simmering water, heat the peanut butter with the butter and milk chocolate, stirring constantly, until smooth and melted. Remove from the heat and fold in the Rice Krispies. Spread the mixture all over the meringue rectangle. Transfer to the freezer and let cool completely.
Make the ganache: In a medium bowl set in a saucepan of simmering water, melt the chocolate. Whisk in the cream until smooth. Remove from the heat and refrigerate for 1 hour, whisking occasionally, until thick enough to spread.
Assemble the cake: Place the bottom cake layer cut side up on a large board. Spread one-third of the ganache over the cake. Invert the filling onto the cake and peel off the paper. Spread half of the remaining ganache over the filling, then top with the second cake layer. Refrigerate until firm, at least 1 hour. Using a serrated knife, trim the edges. Spread the remaining ganache over the top and sides of the cake and refrigerate to set. Cut and serve.
The cake can be refrigerated for up to 4 days.