Preheat your oven to 350°F (175°C).
Grease two 9-inch round cake pans with vegetable oil or butter, then dust with gluten-free flour.
In a large mixing bowl, whisk together the gluten-free flour, granulated sugar, baking soda, baking powder, salt, and cocoa powder.
In another bowl, mix the vegetable oil, buttermilk, eggs, red food coloring, vanilla extract, and white vinegar until smooth.
Gradually add the wet ingredients to the dry ingredients and mix gently until just combined.
Add the red food coloring to the batter and stir until evenly distributed.
Divide the batter evenly between the prepared cake pans and bake for 25-30 minutes.
Once baked, let the cakes cool in the pans for about 10 minutes before transferring to a wire rack to cool completely.