Gluten Free Red Velvet Cake

Why I Love This Recipe
My wife was misdiagnosed for a year as having celiac disease (in actuality it turned out to be Grave's Disease, but that is another story). The restriction for celiac disease is to eat no gluten. That means no wheat, barley, etc. Well I bake and I not only adopted a GF lifestyle to match hers, I played with recipes to make GF baking (using other flours that don't have gluten, such as rice, potato, tapioca, etc).
I got ambitious for a friend's birthday, my friend loves red velvet cake and I thought it couldn't be hard (I had never made red velvet cake before). Here is the recipe that came out of my testing.
I thought not only did this come out moist (the other red velvet cake I had eaten before was dry), all my friends thought it was good. Hopefully this will help those of you GF (even though now I am no longer GF, since my wife's diagnosis changed.
Ingredients You'll Need
Cake
* 4 tablespoons unsweetened cocoa powder
* 1 ounces red food coloring
* 1 cup buttermilk
* 1 teaspoon salt
* 1 teaspoon vanilla extract
* 1 cup vegetable oil
* 2 cups white sugar
* 3 eggs
* 1 1/4 cups rice flour, sifted
* 3/4 cup of potato flour, sifted
* 1/2 cup of tapioca flour, sifted
* 1 1/2 tsp xantham gum
* 2 teaspoons baking soda
* 1 teaspoon white vinegar
Frosting
* 1 cup milk
* 5 tablespoons rice flour
* 1 cup white sugar
* 1 cup butter
* 1 teaspoon vanilla extract
Directions
First I should probably explain the reasoning behind the changes. First since it is supposed to be a gluten free recipe, this means no wheat products of any kind. A 3 part rice flour, 2 part potato flour, 1 part tapioca flour results in a rather good consistency to mimic heavy baking. Using only one type of flour is possible, but it can either not be heavy enough, too grainy, etc. By combining multiple types of flour you can still have a heavier flour with less grainy texture since its cut with finer flour.
Gluten free baking is always dryer, this is why the eggs are increased and why I went with a variant in the reviews of the above referenced recipe in using oil. Moisture is important, it prevents the drying out of the baked good. I also add extra cocoa and sugar because gluten free food needs more flavoring to have the right flavor. I am not sure why GF flour is harder to flavor, but this generally means you need to add 50% more of whatever flavors you are using so the taste can go through.
In addition, GF baking takes longer to bake, I generally add 20% or more to the baking time. However, there are times this is not the case so I keep an eye out on the baking as soon as the original time has passed. I also recommend if you have problems to turn down the heat and bake even longer, the sides and top of any GF baked good can be overcooked if not watched.
1. Grease two 9 inch round pans. Preheat oven to 350 degrees F. Make a paste of cocoa and food coloring. Set aside.
2. Combine the buttermilk, salt and 1 teaspoon vanilla. Set aside. In a large bowl, cream together the shortening and 2 cups sugar until light and fluffy. Beat in the eggs one at a time, then stir in the cocoa mixture. Beat in the buttermilk mixture alternately with the flour, mixing just until incorporated. Stir together baking soda and vinegar, then gently fold into the cake batter.
3. Pour batter into prepared pans. Bake in the preheated oven for 45 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool completely before frosting. Refrigerate until ready to serve.
4. To Make Icing: In a saucepan, combine the milk and 5 tablespoons flour. Cook over low heat, stirring constantly, until mixture thickens. Set aside to cool completely. Cream together butter, 1 cup sugar and 1 teaspoon vanilla until light and fluffy, then stir in the cooled milk and flour mixture, beating until icing reaches spreading consistency. The icing wasn’t the best, I think I would prefer a whipped cream frosting, but everyone has their favorite and this is the frosting I used for the cake.