Spray the inside of a microwave safe mug with non-stick spray (you want to use a mug that holds at least 8 ounces). Add the cake mix, water, and applesauce to your mug. Stir the ingredients together until smooth. (You can add sprinkles on top before baking to add a bit of color!)
Bake in the microwave at full power for 1 minute.
Allow to cool slightly before eating.
Garnish with whip cream, frosting or even ice cream and top with sprinkles!