Preheat oven to 350 and spray a donut pan with pam baking spray
Using a large bowl, whisk together flour, baking soda, salt, cocoa, and sugar until combined
Whisk in the milk, oil, egg, red food coloring, vanilla and vinegar until combined and batter is smooth
Spoon batter into donut pan about ½ way full
Bake in the oven for 10-12 minutes or until they are set
Allow to cool for a few minutes before removing and placing onto a wire rack