Preheat oven to 350 degrees.

If you have a bowl that fits at least 12 cups of ingredients, go ahead and make this batch as the ingredients are listed above for a 4-layered cake. However, if you do not, halve the ingredients and make two batches. (Half of ⅓ c. = 3 T.+1 t. )

Combine butter and sugar in a large bowl of a high speed mixer. Mix for 2 minutes on medium speed.

In a separate bowl, combine white rice flour, tapioca starch, xanthan gum, baking powder, and salt. Add in about 1 c. of dry ingredients to the butter/sugar bowl. Mix for 30 seconds.

Add eggs, one at a time, mixing well after each addition. Add in vanilla and almond extract.

Add remaining dry ingredients and buttermilk alternatively, starting and ending with dry ingredients. Beat for an additional minute to make batter light and fluffy.

Fill four well-greased 9-inch round cake pans with even amounts of cake batter. Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.

Let cool for 5-10 minutes before flipping out.

Cream butter, 2 c. powdered sugar and egg white in the bowl of an electric mixer.

Alternatively add 1 c. sugar and 1 T. milk until all sugar is added.

Add in vanilla, salt and food coloring, if desired.

Prep your cake for the rainbow icing instructional video by using the first batch of frosting. Place the first layer down, ice the top with a ¼- ½ inch layer of frosting and repeat with the remaining 3 layers.

Trim any uneven edges around the cake and finish the cake prep by applying the remainder of the frosting on the sides of the cake.