So, after I made three or four chocolate sheet cakes in a row I suddenly began to wonder if there was a vanilla version of the Texas Sheet Cake, and (if so) if it would translate well to gluten free. I was a little hesitant to try it because I had the idea in my head that chocolate cakes always transition to GF better than vanilla ones. But I had a free afternoon, so I tried it. I found a recipe here and modified it to be a little closer to my original chocolate version. So far I've made it twice, and it's been a big hit each time, with people fighting over the last piece :)
Vanilla Texas Sheet Cake
2 c. EGF all-purpose flour
2 c. sugar
1 tsp. xanthan gum
1 tsp. baking soda
1/2 tsp. salt
1 c. butter (2 sticks)
1 c. water
1/2 c. buttermilk (I use 1/2 c. whole milk plus about 1.5 tsp. lemon juice)
3 eggs
1 tsp. vanilla
In a large bowl, combine flour mix, sugar, xanthan gum, baking soda, and salt. In a medium pan, combine butter and water. Bring to a boil over medium high heat, stirring occasionally. Pour butter mixture into flour mixture and mix well until smooth. Add buttermilk, eggs, and vanilla and mix thoroughly. The batter will be quite thin.
Pour batter into a greased (or well-sprayed-with-Pam) 13x18 sheet cake pan. Bake at 400 degrees for 20-25 minutes. (The edges of the cake will pull away from the pan when the cake is done.) Remove from the oven and, while hot, top with the following frosting:
Browned Butter Frosting
1/2 c. butter (1 stick)
5 c. powdered sugar (about 1 1/3 lb.)
6 Tbs. milk
1 tsp. vanilla
Melt butter in a medium saucepan over medium-low heat, stirring continually, until butter is a light brown color and aromatic. (If you burn the butter, don't use it. Throw it out and start again.) Add powdered sugar a cup or so at a time, stirring until well incorporated each time and adding milk as necessary to keep the mixture mixable. Remove from heat and add any remaining milk and the vanilla. Mix well with a hand mixer or stand mixer until smooth.