3 1/2 c. cake flour, spooned and leveled
2 1/2 tsp. baking powder
3/4 tsp. baking soda
1/2 tsp. kosher salt
1 c. (2 sticks) unsalted butter, at room temperature
1 1/2 c. granulated sugar
6 large egg whites, at room temperature
2 tsp. pure vanilla extract
1 1/2 c. buttermilk, at room temperature
3 candy canes, crushed (about 1/4 cup)
Store-bought peppermint bark, roughly chopped, for decorating
- Preheat oven to 325°F. Lightly grease three 8-inch round cake pans and line with parchment; grease parchment. Whisk together flour, baking powder, baking soda, and salt in a bowl.
- Beat butter and sugar with an electric mixer on medium-high speed until pale and fluffy, 3 to 4 minutes. Add egg whites, one at a time, beating just until incorporated after each addition. Beat in vanilla. Reduce mixer speed to low and beat in flour mixture and buttermilk, alternately, beginning and ending with flour mixture, just until incorporated. Divide batter among prepared pans.
- Bake until a wooden pick inserted in center comes out clean, 25 to 30 minutes. Cool in pans on wire racks, 5 minutes, then invert onto racks to cool completely.
- Place one cake layer on a cake stand or plate. Top with 1 cup frosting and sprinkle with half of the crushed candy canes. Repeat one more time. Cover top and sides of cake with remaining frosting. Press bark into frosting on the sides of the cake.