Preheat oven to 350° and grease a 9"-x-13" baking dish with cooking spray. Combine peaches along with syrup and cinnamon in prepared baking dish and stir to combine.
Pour cake mix over peaches in an even layer. Layer butter evenly on top.
Bake until fruit is bubbly and cake is cooked through, 50 to 55 minutes.
Serve with ice cream.
