Serve a crowd with this delicious gluten free chocolate sheet cake. This gf Texas sheet cake is moist and fluffy, and it's easy to slice for big occasions.
¾teaspoonxanthan gumomit if your blend already contains it
5tablespoons(25g)unsweetened cocoa powder(natural or Dutch-processed)
1 ½cups(300g)granulated sugar
¾teaspoonbaking soda
¼teaspoonkosher salt
12tablespoons(168g)unsalted buttermelted
¾cup(6fluid ounces)brewed coffeeat room temperature
¾cup(168g)sour cream or plain Greek yogurtat room temperature
1(50g (weighed out of shell))eggat room temperature, beaten
1(25g)egg yolkat room temperature, beaten
1teaspoonpure vanilla extract
For the icing
3cups(345g)confectioners’ sugar
5tablespoons(5g)unsweetened cocoa powder(Dutch-processed, if possible)
¼teaspoonkosher salt
12tablespoons(168g)unsalted butterchopped
7tablespoons(3 ½fluid ounces)milk
1teaspoonpure vanilla extract
Nonpareilsfor sprinkling (optional)
Instructions
Preheat your oven to 325° F. Line a half sheet pan (13 x 18 x 1 inches) with unbleached parchment paper and set it aside.
For the cake.
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.
Pour the melted butter, coffee, sour cream, egg and vanilla, and mix until just combined.
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 in color and springs back readily when pressed gently with a finger, about 20 minutes.
For the icing.
During 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, pour the hot butter and milk mixture over the dry ingredients, add the vanilla, 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. Sprinkle immediately with the (optional) nonpareils.
Allow the cake to cool completely in the pan to room temperature.
For easier slicing, chill the cake, then lift it out of the pan by the parchment paper. Slice it into 12 to 16 generous pieces, and serve chilled or at room temperature.
Notes
Originally published as Gluten Free Texas Sheet Cake on the blog in 2012. In 2018, recipe scaled up 150% and baked in a half, rather than a quarter, sheet pan, photos and video new. In 2022, some new photos, text resources added.