In one large mixing bowl, mix the flour, cocoa powder, brown sugar, and baking powder.
In another bowl, mix the buttermilk, butter, vanilla extra, and egg.
Then mix the wet ingredients into the dry ingredients, mix well, and then mix in the food coloring.
Grease your donut pan.
Fill the donut cavity with the batter.
Set the pan into the air fryer for 12-16 minutes at 320 degrees F, air fryer setting.
Test the donuts with a toothpick, when it comes out clean remove. Note: all air fryers cook at slightly different timing.
Let cool before adding the cream cheese frosting.
Plate, serve, and enjoy!