White Chocolate Layer Cake
"This is the kind of homey buttermilk cake that is incredibly comforting to consume. The crumb is soft, moist, and remarkably
light. It's known to disappear-along with tall glasses of milk-faster than you can say, well, "white chocolate"."
Cake
4 ounces finely chopped white
chocolate
1/2 cup boiling water
1/2 pound unsalted butter, at room
temperature
2 cups sugar
4 large eggs, separated, at room
temperature
1 teaspoon vanilla extract
2 1/2 cups cake flour
1 teaspoon baking soda
1/2 teaspoon salt
1 cup buttermilk
Icing
6 ounces finely chopped white
chocolate
3/4 pound cream cheese, at room
temperature
3 tablespoons unsalted butter, at
room temperature
3/4 teaspoon vanilla extract
2 1/2 to 3 cups confectioners' sugar, or
to taste
Make the cake:
1. Position the racks in the upper and lower thirds and preheat oven to 350 degrees F. Lightly butter the bottoms of three 8-inch round cake pans. Line the bottom of each pan with parchment paper. In a double boiler over hot-not simmering-water, melt the white chocolate, stirring frequently. Beat in the water and set aside.
2. Using an electric mixer set at medium speed, cream the butter and sugar in a large bowl until light and fluffy. Beat in the egg yolks, one at a time, beating well after each addition. Stir in the white chocolate mixture and the vanilla.
3. Into a medium bowl, sift the flour, baking soda, and salt together. Beat the flour mixture into the white chocolate mixture, alternating with the buttermilk, until smooth.
4. Using an electric mixer set at low speed, beat the egg whites in a grease-free medium bowl until they start to foam. Gradually increase the speed to high and continue beating until the egg whites form stiff, shiny peaks. Fold one-fourth of the egg whites into the white chocolate mixture to lighten it; fold in the remaining egg whites.
5. Pour the cake batter into the prepared pans and bake until a cake tester inserted in the centers of the pans comes out clean, about 30 to 40 minutes. Transfer to wire racks to cool for 30 minutes. Invert layers from pans onto the wire racks, peel off the parchment paper, and cool completely.
Make the icing:
6. In a double boiler over hot-not simmering-water, melt the white chocolate, stirring frequently. Transfer to a large bowl. Let stand until almost completely cool. Using an electric mixer set at medium speed, beat in the cream cheese, butter, and vanilla. Add the confectioners' sugar, a little at a time, to make an icing consistency.
Assemble:
7. Place a cake layer on a serving platter. Spread one-fourth of the icing over the cake layer. Top with the second layer and spread with one-fourth of the icing. Top with the third layer and evenly frost the top and sides of the cake with the remaining frosting, swirling decoratively. Refrigerate. Bring to room temperature before serving.
Do ahead: The unfrosted layers can be frozen up to 1 month. The frosted cake can be made and refrigerated up to 2 days in advance.
Makes 8 to 10 servings.