Add the flour, cocoa powder, sugar, baking powder, and salt to a large mixing bowl.
In another mixing bowl, add the milk, vegetable oil, vanilla extract, and eggs.
Slowly, pour the wet ingredients into the dry ingredients, mix well.
Then slowly pour the water into the mixture.
Spray your muffin tin with olive oil, or if you are using muffin liners, fill the cupcake pan.
Pour the batter into the muffin tins, filling out about 2/3 the way.
Set into the air fryer for 9-12 minutes, at 330 degrees F, air fryer setting.
Let cool before decorating.