- For the cake:
- 1 cup (2 sticks) unsalted butter, room temperature, plus more for pans
- 2 1/2 cups all-purpose flour (spooned and leveled), plus more for pans
- 1/2 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1 teaspoon salt
- 1 1/2 cups sugar
- 2 large eggs plus 3 large egg yolks
- 2 teaspoons pure vanilla extract
- 1 cup low-fat buttermilk
- For the whipped frosting:
- 3 large egg whites
- 3/4 cup sugar
- Pinch of salt
- 1/3 cup water
- 1/4 teaspoon pure vanilla extract
- Preheat oven to 350 degrees. Butter and flour two 8-by-2-inch cake pans, tapping out excess flour.
- In a medium bowl, whisk flour, baking powder, baking soda, and salt.
- In a large bowl, using an electric mixer, beat butter and sugar until light and fluffy. With mixer on low, beat in eggs and yolks, one at a time. Beat in vanilla. Alternately beat in flour mixture and buttermilk, beginning and ending with flour mixture; mix just until combined.
- Divide batter between pans; smooth tops. Bake until cakes pull away from sides of pans, 32 to 35 minutes. Let cool in pans 10 minutes. Run a knife around edges of pans and invert cakes onto a wire rack. Let cool completely.
- Make the whipped frosting: In a heatproof bowl set over (not in) a saucepan of simmering water, combine 3 large egg whites, 3/4 cup sugar, a pinch salt and 1/3 cup water. Cook over medium, stirring constantly, until sugar has dissolved (or mixture registers 150 on an instant-read thermometer), 2 to 3 minutes.
- Transfer to a large bowl. Using an electric mixer, beat on medium-high until glossy, stiff peaks form (do not overbeat), about 3 minutes; reduce speed to low, add 1/4 teaspoon pure vanilla extract, and beat just until combined.
- Place one cake, bottom side up, on a cake stand. Tuck strips of parchment paper underneath. Using an offset-spatula or table knife, spread top with whipped frosting. Top with remaining cake; frost top, then sides.
Make ahead: Store unfrosted cakes at room temperature up to 1 day. Once frosted, serve within a few hours.
- Desserts, Cake
- North American