Spray a 9x13-inch baking dish with cooking spray.
Peel, core, and slice the apples into ½-inch chunks and transfer to the baking dish. In a small bowl, combine the granulated sugar and cinnamon. Sprinkle the cinnamon sugar mixture over the apples. Sprinkle the cake mix evenly over the apples. Pour the melted butter over the cake mix, evenly covering as much of the cake mix as possible.
Bake the cake until the top is lightly golden and the apples are tender, 50 to 55 minutes. Remove from the oven and serve warm with a scoop of ice cream. Store any leftovers covered in the fridge for up to 3 days. Reheat in the oven or microwave before serving. Love the recipe? Leave us stars and a comment below!
