If you grew up with one version or another of Texas Sheet Cake, you’re way ahead of me, sister. I now know, and am teaching my children, that raising a child without this perfect gluten free chocolate cake that is not too rich and not too sweet but just the right amount of everything is nothing short of blasphemy.
A few weeks (a few days?) back, some of you were all, gluten-free Texas Sheet Cake gluten-free Texas Sheet Cake in the comments of a particular blog post (which I can’t remember).
So I researched lots and lots of recipes, and compiled what I thought were the best parts of what’s out there. Like my own little America’s Test Kitchen. I tweaked a few things, but not to make it fancy schmancy. Don’t worry. I realize that fancy schmancy is not the point of a Texas Sheet Cake. I tweaked to make sure that it held up as a gluten-free version. The proportions are a bit changed, but the basic technique is there.
A pourable batter.
That’s smoothed out in a rimmed baking sheet (I cut the recipe in half so it fits in a quarter sheet pan, because it’s easily doubled, and a half sheet pan of cake is, well, a lot of cake).
It’s baked it just until it springs back when pressed gently.
With hot icing poured quickly on the hot cake. In my virgin Texas Sheet Cake voyage, I learned that you must spread out the icing quickly, before it begins to set or it will wrinkle like a raisin in the sun. Like a baked apple. Like a Shar Pei.
Don’t worry if the icing has a few bubbles and lumps. They’ll even out as the cake cools.
First, make the cake. Preheat your oven to 325° F. Line a quarter sheet pan (9-inches x 13-inches) with unbleached parchment paper and set it aside.
In a large bowl, place the flour, xanthan gum, cocoa powder, sugar, baking soda and salt, and whisk to combine well. Set the bowl aside. In a small saucepan, heat the butter and coffee on medium heat, stirring occasionally, until the butter is completely melted. Pour the melted butter and coffee mixture over the dry ingredients, and mix to combine. Add the sour cream, egg and vanilla, and mix to combine. Pour the batter into the prepared sheet pan, and spread into an even layer with a wet spatula. Place the baking sheet into the preheated oven and bake until the cake is uniform and springs back readily when pressed gently with a finger, about 20 minutes.
During the last 10 minutes of the cake’s baking, make the icing. In a large bowl, place the confectioners’ sugar, cocoa powder and salt and whisk to combine well. Set the bowl aside. In a clean small saucepan, place the butter and the milk, and cook over medium heat, stirring occasionally, until the butter is completely melted. Remove the saucepan from the stove, add the vanilla and mix to combine. Pour the hot butter and milk mixture over the dry ingredients, and mix to combine.
Ice the cake. As soon as the cake is finished baking, remove the pan from the oven and pour the hot icing over the hot cake. Working quickly to ensure that the icing is spread before it sets, with an offset spatula or butter knife, spread the icing over the entire surface of the cake with a wet spatula. Allow the cake to cool completely in the pan to room temperature. Lift the cake out of the pan by the parchment paper once it is cool. Slice into 12 to 16 pieces, and serve chilled or at room temperature. The cake is easiest to slice with a warm, sharp knife when the cake itself is cold.