For the waffles, preheat your waffle iron according to the manufacturer’s directions. Whisk together flours, cocoa powder, baking powder, salt, and sugar. Make a well in the center of the dry ingredients and add the milk, oil, and vanilla extract to the center. Whisk together the wet ingredients until incorporated and then fold the dry ingredients into the wet until a thick batter has formed. Bake the waffles according to your waffle iron’s directions.