Preheat oven to 350 degrees.
Coat a 3 quart baking dish with cooking spray and pour in mixed berries.
Sprinkle brown sugar over berries, then toss to combine.
Mix in shredded coconut and 2 cups granola.
Spread remaining 1 cup granola on top of mixed berry concoction.
Bake at 350 degrees until berries are bubbling and granola topping has lightly browned, approximately 40 to 45 minutes.
Cool for 15 minutes before serving.