Lemonade Layer Cake Recipe

In a large bowl, beat butter and sugar until crumbly, about 2 minutes. Add the lemonade concentrate, lemon peel and vanilla; mix well. Add eggs and egg whites, one at a time, beating well after each addition. Combine the flour, baking powder, baking soda and salt. Add to the butter mixture alternately with buttermilk, beating well after each addition. Coat two 9-in. round baking pans with cooking spray and dust with flour. Pour batter into prepared pans. Bake at 350 ° for 18-22 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes before removing from pans to a wire rack to cool completely. For frosting, in a small bowl, combine cream cheese and butter until smooth. Add the lemon peel, lemonade concentrate and vanilla; mix well. Gradually beat in confectioners' sugar until smooth. Spread frosting between layers and over top and sides of cake. Refrigerate for at least 1 hour before serving. Refrigerate leftovers.