Preheat oven to 350 degrees F
Lightly spray 13x9 baking dish
Add peaches to baking dish
Sprinkle cake mix over fruit
Slice butter into narrow pieces and place on top of cake mix. Be sure it is mostly covered with butter.
Bake at 350 degrees F for 45- 50 min or until fruit is bubbling and cake is brown
Remove from oven to cooling rack
Serve warm or room temperature with ice cream or whipping cream