Fabulously Yummy Gluten Free Chocolate Sheet Cake

Being Gluten free I miss a good cake!  

 I have always liked chocolate sheet cake but thought I would never be able to make a good gluten free one.  Alas I found this gluten free version of the Pioneer Woman's best chocolate sheet cake ever!  It truly lives up to its name!!!  

It really was not hard to make at all...well worth the effort! 

For those who are not gluten free you can use the same recipe just substitute the 3 kinds of flour for 2 cups regular all purpose flour and take out the xanthan gum. 

Best Gluten-Free Chocolate Cake. Ever adapted from The Pioneer Woman Cooks
For the Cake
Dry Ingredients
1 cup white rice flour
1/2 cup sweet rice flour
1/2 cup cornstarch
2 cups granulated sugar
1 teaspoon Baking Soda
1/4 teaspoons salt
1/8 teaspoons xanthan gum
Wet Ingredients
2 sticks butter
5 Tablespoons natural cocoa powder (yes, this is a wet ingredient.)
1 cup boiling water
1/2 cup buttermilk
2 large eggs
1 teaspoon vanilla extract

1. Preheat oven to 350 degrees F. Grease a 12x18x1 pan with nonstick cooking spray. Set aside.
2. In a large bowl, whisk together the dry ingredients. Set aside.
3. In a medium saucepan, melt the butter over medium heat. Add cocoa powder and stir to combine.
4. Reduce heat to low and allow mixture to cook for 3 minutes.
5. Stir in boiling water and cook for 30 seconds.
6. Remove from heat and allow to cool for 30 seconds.
7. Pour mixture over dry ingredients. Stir to combine. (You can use a balloon whisk for this.) Blend until smooth.
8. Add buttermilk, eggs, and vanilla, Mix until a batter forms.
9. Pour batter evenly into prepared pan.
10. Bake for 25 minutes or until cake springs back to the touch.
11. Remove cake from the oven.
12. Prepare icing. (Recipe below.)
13. Pour icing over the warm cake.

For the Icing
Baker's note: Ree's recipe contains 1/2 cup finely chopped pecans. I am not a big fan of nuts neither are my kids, so, I've omitted them. If you like nuts, add them! Simply stir the nuts into the icing right before pouring it over the cake.
1 1/2 stick butter
5 tablespoons natural cocoa powder
3 1/2 cups powdered sugar
6 Tablespoons Milk
1 teaspoon vanilla extract

1. In a large saucepan, melt the butter over medium heat.
2. Add the cocoa powder. Stir to combine. Reduce heat to low. Add the powdered sugar, milk and vanilla extract. Using a whisk, mix until smooth and shiny. (If you are using nuts, add them now.)
3. Pour evenly over warm cake.