Gather all ingredients. Preheat the oven to 375 degrees F (190 degrees C).

Empty peaches into a 9×13-inch baking dish.

Cover peaches with dry cake mix and press down firmly.

Cut or grate butter into small pieces and scatter on top of cake mix. Sprinkle top with cinnamon.

Bake in the preheated oven until peaches are hot and bubbling and top of dump cake is golden brown, about 45 minutes.