Gluten-Free Chocolate Sheet Cake with Chocolate Buttercream
recipe by: Sarah Menanix
yields: 24pieces, 9x13 sheet cake, 24 servings
prep time: 20 minutesmins
cook time: 50 minutesmins
total time: 1 hourhr10 minutesmins
The BEST gluten-free chocolate cake recipe, bar none. With a thick swirl of chocolate buttercream and festive sprinkles, this is the perfect gluten-free chocolate birthday cake. Bake as cupcakes or a layer cake!
4.91 from 20 reviews
Ingredients
Gluten-Free Chocolate Sheet Cake
Scant 1 cup milk (1 cup minus 1 tablespoon), or equivalent in buttermilk and skip the vinegar
1tablespoonwhite vinegar
168gsweet rice flour, also called Mochiko - different from "white rice flour" or "brown rice flour"
Preheat the oven to 350°F. Prepare a 9x13 cake pan by lightly oiling it, and lining it with parchment paper. See notes for converting to cupcakes or a layer cake.
If not using buttermilk, combine the milk and vinegar in a small cup and let sit while you measure the flour, at least 5 minutes.
In a large bowl, sift together the sweet rice flour, oat flour, millet flour, cocoa powder, sugar, baking powder, baking soda, and salt.
In the measuring cup, whisk the milk and vinegar mixture with the egg, oil, vanilla extract, and chocolate extract until smooth. Pour this mixture into the dry ingredients and stir lightly. Pour the hot water into the dry ingredients and mix until completely smooth, scraping up the sides and bottom to completely incorporate.
Pour the batter into the prepared cake pan and bake for about 45-55 minutes, or until a toothpick inserted in the center comes out clean or with just a few moist crumbs and the center bounces back when poked. In my experience, it's best to err on the side of an extra minute or two to be sure - this cake is very moist and won't over-bake very easily.
Let cool in the pan for 10 minutes, then overturn the cake onto a wire rack to cool completely. To do this, I place a large sheet pan over the baking pan and, holding it together, carefully flip the cake to release. Peel off the parchment paper, then place a wire rack over the top, and carefully flip right side up.
While the cake cools completely, prepare the frosting. In the bowl of a stand mixer fitted with the paddle attachment, cream the butter over medium speed.
Sift together the powdered sugar, cocoa powder, and salt. Slowly add this to the butter, in 4 batches, beating until incorporated. Add the vanilla and chocolate extracts and mix until smooth. Add the milk or cream, starting with just 2 tablespoons and adding additional milk or cream as needed, until frosting is smooth and spreadable. It should be somewhat glossy, but still hold swirls.
When the cake has cooled, swirl the buttercream over the top of the cake (I recommend using the back of a soup spoon) and top with colorful sprinkles, if desired. Slice into 24 pieces and devour.
Notes
The same exact batter quantity in this recipe makes:
1 9x13 cake - bake for 45-55 minutes
3 8-inch layer cakes - bake for 33-37 minutes
36 cupcakes - bake for 18-22 minutes
To adjust the recipe to make different quantities, scale all the ingredients to 1, 2, or 3 eggs. I've got a post with each scaled version below to save you the trouble. Here's what scaling the recipe down gets you:
This nutritional information has been automatically calculated, and as such, may be incomplete or inaccurate. Please reference the specific ingredients you use for the most accurate nutritional information.