Dry Ingredients

2 ⅔ cups gluten-free all-purpose baking flour (with xanthan gum), sifted

1 cup unsweetened cocoa powder, sifted

1 ½ teaspoons baking powder

1 teaspoon baking soda

½ teaspoon salt

Wet Ingredients

1 cup milk (dairy or non-dairy)

1 cup granulated sugar

¾ cup light brown sugar

3 large eggs

1 teaspoon white vinegar or apple cider vinegar

1 tablespoon pure vanilla extract

⅔ cup neutral oil (avocado, canola, safflower, or similar)

1 cup hot brewed coffee or boiling water

Chocolate Buttercream

¾ cup butter (1 ½ sticks), softened (dairy or plant-based)

½ cup unsweetened cocoa powder, sifted

3–5 cups powdered sugar, sifted

2–4 tablespoons milk (dairy or non-dairy)

2 teaspoons vanilla extract

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Preheat & Prep: Preheat oven to 350°F (175°C). Grease and line a 9×13 pan or two 8-inch pans with parchment.
Mix Wet Ingredients: In a large bowl, whisk milk, sugars, eggs, vinegar, vanilla, and oil until smooth.
Add Dry Ingredients: Sift flour, cocoa, baking powder, soda, and salt. Gently whisk into wet ingredients until just combined.
Add Coffee/Water: Slowly whisk in hot coffee or boiling water. Batter will be thin.
Bake: Pour into pan(s). Bake 35–45 min for 9×13, 32–37 min for layers. Toothpick should come out clean. Cool 10–20 min, then transfer to a rack.
Make Buttercream: Beat butter until creamy. Add cocoa powder, powdered sugar, milk, and vanilla until smooth.
Frost & Serve: Spread buttercream on cooled cake. Decorate as desired.

Use a gluten-free flour blend that contains xanthan gum. If your blend does not include it, add ½ teaspoon xanthan gum to the dry ingredients.
Sifting cocoa powder and powdered sugar prevents lumps and ensures a smooth batter and frosting.
The hot coffee enhances the chocolate flavor without making the cake taste like coffee. Boiling water may be substituted.
Do not overmix the batter. Overmixing can cause the cake to sink in the center.
For dairy-free frosting, use plant-based butter and non-dairy milk.
Cake layers can be frozen unfrosted for up to 2 months. Wrap tightly in plastic wrap and thaw at room temperature before decorating.
Store frosted cake in an airtight container at room temperature for 3–4 days or refrigerate up to 1 week.