Lemonade Cake

Allow butter and eggs to stand at room temperature for 30 minutes. Meanwhile, grease a 13x9x2-inch baking pan; set aside. In a medium bowl stir together flour, baking powder, baking soda, and salt; set aside.

Preheat oven to 350°F. In a large mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Gradually add sugar, about 1/4 cup at a time, beating on medium speed until well combined. Scrape sides of bowl; beat for 2 minutes more. Add eggs, one at a time, beating well after each addition. Beat in lemonade concentrate and vanilla. Alternately add flour mixture and buttermilk, beating on low speed after each addition just until combined. If desired, stir in a few drops of yellow food coloring. Spread batter into prepared pan.

Bake for 30 to 35 minutes or until top springs back when lightly touched. Cool in pan on a wire rack. Spread cake with Lemon Butter Frosting. If desired, garnish with lemon slices (slices should be removed before eating).