One-Bowl Gluten-Free Chocolate Cake

Ingredients

• Gluten-free non-stick cooking spray or 16 paper cupcake liners
• 1 1/4 cups white rice flour
• 1 cup granulated sugar
• 1/4 cup potato starch
• 1/4 cup cocoa powder
• 1 1/4 teaspoons baking powder
• 3/4 teaspoon table salt
• 1/2 teaspoon xanthan gum
• 1/2 cup vegetable oil
• 2/3 cup coffee or water
• 3 large eggs
• For the fluffy coconut buttercream:
• 1/2 cup coconut oil, softened but not melted
• 3/4 cup confectioners' sugar
• 1 jar marshmallow crème
• 1 teaspoon vanilla extract
• 1 cup shredded coconut, optional

Directions

1. For the cake: Place the oven rack in the center of the oven and heat it to 350 degrees F. Coat a square cake pan measuring 9 by 9 by 2 inches with nonstick cooking spray, or line 16 standard cupcake cavities with paper liners. Put the prepared pan or pans to the side.
2. In a large mixing bowl, whisk the white rice flour, granulated sugar, potato starch, cocoa powder, baking powder, salt, and xanthan gum until evenly combined. Pour in the vegetable oil and coffee, then add the eggs. Beat with a handheld mixer until the batter turns thick, about 1 minute.
3. Transfer the batter to the prepared cake pan and smooth it into an even layer, or divide it among the cupcake liners. For cupcakes, fill each cavity about 2/3 full. Bake until a cake tester poked into the middle comes out clean, about 40 minutes for the square cake or 18 minutes for cupcakes. Cool the cake on a wire rack. If making cupcakes, take them out of the pan after 5 minutes. Frost once completely cool. If you like, scatter coconut over the cake or press the frosted cupcake tops into coconut.
4. For the buttercream: In a medium mixing bowl, beat the coconut oil with the confectioners’ sugar until pale and fluffy, about 30 seconds. Use high speed with a handheld mixer, or medium-high speed with a stand mixer. Add the marshmallow crème and vanilla, then beat until fluffy. Spread over the cooled cake or cupcakes.