LEMON-LIME LAYER CAKE

Steps:

• Preheat oven to 350 degrees. Lightly spray with baking oil and flour two 8-by-2-inch cake pans. Make sure to tap out the excess flour. In a bowl, whisk together flour, baking powder, baking soda, salt, and lemon zest.
• In a large bowl mixing bowl and using an electric mixer, or use your KitchenAid mixer like me, cream together butter and 1 1/2 cups sugar until light and fluffy. Reduce mixer speed to low and add in eggs and yolks, one at a time. Mix in 4 tablespoons lemon juice. Alternate adding in flour mixture and buttermilk beginning and ending with flour. Mix until well combined. Pour ½ of the batter into one pan and add the remaining to the second pan. Place in oven and bake for 30-34 minute or until cake starts to pull away from the sides of the pan. Once cakes are completely cooked remove from the oven and cool. Allow the pans to cool for 10 minutes on a cake rack, then remove cakes from the pans and place back on cake rack, allowing them to completely cool.
• While the cakes are cooling, make lime buttercream. In a large bowl, cream together the confectioners' sugar and butter until smooth. Gradually mix in the milk, lemon flavoring, lime zest and juice with an electric mixer until smooth and stiff, about 5 minutes. Color with food coloring if desired.