Preheat oven to 350 degrees. Prepare a 13×9 pan with nonstick spray.
In a medium bowl, stir together the berries, sugar and sinnamon. Spread in the bottom of the cake pan.
Sprinkle on ½ of the rolled oats, then cake mix, then remaining oats. Next add the butter.
Bake for about 30 minutes until bubbly and golden.
Serve it with ice cream or whipped cream. Enjoy.