Preheat oven to 350?F.
Spray 9 x 13 baking dish with non-stick cooking spray.
Spoon apple on bottom of the dish.
Make cake mix according to the box directions (or using the diet soda version works as well).
Pour cake batter on top the apples.
Melt butter with water and pour on top of cake batter.
Bake for 70 minutes
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