Rainbow Butter Cake Yield: 16 servings 1 1/4 cups (2 1/2 sticks) butter at room temperature 2 1/4 cups granulated sugar 5 eggs 4 1/2 cups cake flour 4 1/2 teaspoons baking powder 1 1/2 cups milk 1 1/2 teaspoons vanilla extract Paste food colorings in 3 shades Preheat oven to 350 degrees F. Grease a 10-inch tube pan and set aside. In a large bowl of an electric mixer, combine butter and sugar until smooth, about 3 minutes. Add eggs, one at a time, beating well after each addition and scraping down the sides of the bowl with a rubber spatula. Combine flour and baking powder and slowly add to butter-egg mixture alternately with milk. Add vanilla extract and beat until combined. Divide batter into three equal portions and color each with about 1/4 teaspoon of paste food coloring. Mix until color is well-distributed. Spoon one portion of colored batter into prepared pan and smooth top. Repeat with remaining portions. Bake for 70 minutes. Remove from oven to wire rack and cool for 10 minutes in pan. Release from pan and cool completely. Frost with favorite icing, if desired.