Preheat your oven to 350 degrees. Spray a 9x13 inch glass baking dish with cooking spray.
In a small bowl, mix the pumpkin, cinnamon, and nutmeg together.
Spread the apple pie mix over the bottom of the pan. Spread the pumpkin over that. Sprinkle the cake mix (just the cake mix, none of the mix ins) over the pumpkin. Then cut the butter into equal pieces and set the tabs of butter on top of the cake mix.
Bake for 40 to 45 minutes uncovered or until the edges begin to brown.