Peel, core, and slice your apples. Apples should be think and bite sized
Spray crockpot with cooking spray.
Place apples in the bottom of your crockpot. Sprinkle with sugar and 1/2 tsp cinnamon.
Place the cake mix in a large bowl. Add the oats and 1 tsp cinnamon. Stir, then sprinkle over the top of the apples.
Drove slices of the butter over the top of the cake mix.
Cover and cook on high for 4 hours. All crockpots cook differently. Yours might take less time. Start checking at 1 1/2 hours.
Once all the butter is melted and the powder is gone and the top is golden, it is done.I sometimes start with a paper towel between the lid and insert, but with this cake I like to remove it after about 2 hours so the condensation helps to dissolve the cake mix. Once you bake in your crockpot awhile you'll learn how it bakes (faster/shorter. hotter etc ) Serve with ice cream or whipping cream