Pre-heat oven to 350 degrees and place liners in two cupcake or muffin tins (if you only have one, you can bake in batches).
In a large bowl sift together oat flour, raw sugar, baking powder, baking soda, salt, and cocoa powder.
In the bowl of a stand mixer or in a separate large bowl, whisk together vegetable oil, buttermilk, eggs, beet juice, vinegar, and vanilla extract.
Add the flour mixture to the liquid mixture and beat with an electric mixer until very smooth, about 2 minutes. Batter will be pretty thin.
Fill the cupcake liners about ½ way full and bake for 20 minutes, rotating the pan after 10 minutes.
Remove cupcakes to wire racks and cool completely before frosting with cream cheese frosting.