In a large mixing bowl, mix the sugar, flour, cocoa powder, baking powder, baking soda, salt, eggs, milk, oil, vanilla extract, and water.
Mix well until smooth.
Spray your cake pan with non-sticking spray.
Pour the batter into the prepared pan, filling about 2/3 way full. Depending on the size of your pan and air fryer, you can fill two cake pans.
Set into the air fryer for 12-15 minutes at 320 degrees F, air fryer setting.
Stick a toothpick into the center of the cake. If it comes out clean, remove the cake; otherwise, continue to air fry until completely baked through.
Let cool before frosting.
Frost the cake.
Plate, serve, and enjoy!