12 tablespoons (1 1/2 sticks) unsalted butter, softened
1 1/2 cups sugar
2 cups all-purpose flour
2 teaspoons baking powder
1/4 teaspoon salt
6 large egg whites
3/4 cup whole milk
2 teaspoons vanilla extract
Preheat oven to 350 degrees.
Prepare two round 9 inch cake pans by buttering sides and lining bottom with parchment paper.
Combine flour, baking powder and salt. Set aside as dry ingredients.
Combine egg whites, milk and vanilla extract. Set aside as wet ingredients.
Cream together butter and sugar in large mixing bowl.
Add wet and dry ingredients to creamed butter in thirds, starting with wet and ending with dry.
Pour batter into prepared pans and smooth top with a spatula. Bake cake for 25 to 30 minutes, or until a toothpick inserted in the center emerges clean. Cool in pans on a rack for 5 minutes, then turn out onto rack, remove paper, and let cool completely.