Buttermilk White Layer Cake

Step 1
Preheat oven to 350 degrees F (175 degrees C). Grease and flour 2 9-inch round baking pans.

Step 2
Beat butter and vanilla extract together in a bowl until creamy. Mix flour, baking powder, baking soda, and salt together in a separate bowl. Beat butter mixture, alternating with buttermilk, into flour mixture until fully incorporated.

Step 3
Beat egg whites in a glass or metal bowl until foamy. Gradually add sugar, continuing to beat until medium peaks form. Lift your beater or whisk straight up: the tip of the peak formed by the egg whites should curl over slightly. Fold egg white mixture into batter until just combined. Pour batter evenly into the prepared baking pans.

Step 4
Bake in the preheated oven until a toothpick inserted in the center of each cake comes out clean, 30 to 35 minutes. Cool in the pans for 10 minutes before removing to cool completely on a wire rack.

Step 5
Spread frosting atop one of the cakes and top with second cake. Spread the remaining frosting over the top cake and around the sides of both cakes.