Preheat oven to 350°F.
In large bowl, gently toss together berries and ½ cup cake mix. Spoon berry mixture into an ungreased 10-inch deep-dish pie pan.
In separate bowl, place remaining cake mix, full pouch cinnamon topping, oats and butter. Combine with fork until mixture is crumbly. Sprinkle topping over berry mixture.
Bake 35-40 minutes or until filling is bubbly. Serve warm with vanilla ice cream, if desired.