Ingredients

1 1/4 c. cake flour

1/4 c. Unsweetened cocoa powder

1/2 tsp. baking powder

2 stick unsalted butter

1/2 c. whole milk

6 large eggs

1 c. sugar

1 pinch salt

1 1/2 c. heavy cream

1 1/2 lb. milk chocolate

Shaved milk chocolate

Preparation

Step 1Preheat oven to 325°. Butter and flour two 9-inch-square cake pans.Step 2In a medium bowl, whisk cake flour, cocoa, and baking powder. In a medium saucepan, melt butter in milk over low heat. Transfer to a large bowl and let cool slightly. Whisk in egg yolks and 1/2 cup of the sugar. Add the dry ingredients and whisk until smooth.Step 3In a clean bowl, beat egg whites with salt until soft peaks form. Gradually add remaining 1/2 cup sugar and beat at medium-high speed until whites are stiff and glossy. Fold beaten whites into the batter until no streaks remain. Divide batter between the pans and bake for 25 minutes, until the cakes are springy and a toothpick inserted in the centers comes out clean. Transfer the cakes to a rack and let cool completely.Step 4Meanwhile, in a medium saucepan, bring cream to a simmer. Put chocolate in a heatproof bowl and pour hot cream on top. Let stand for 3 minutes, then whisk until smooth. Let frosting stand at room temperature, stirring occasionally, until thick enough to spread, about 1 hour.Step 5Turn the cakes out of the pans and put one layer on a plate. Top with 1 cup of frosting, spreading it to the edge. Top with the second layer and spread remaining frosting over the top and sides. Let the cake stand at room temperature for about 30 minutes before cutting into squares.