1.Preheat oven to 375 degrees F (190 degrees C).
2.Empty peaches into the bottom of one 9x13 inch pan.
3.Cover with the dry cake mix and press down firmly.
4.Cut butter into small pieces and place on top of cake mix. Sprinkle top with cinnamon.
5.Bake at 375 degrees F (190 degrees C) for 45 minutes.