Preheat the oven to 350 degrees F.
In a large mixing bowl, toss the berries together. Add the flour, and sugar give it a good toss. Transfer the berries into a lightly greased 8-inch square baking dish.
Crush the dried oats, granola and corn flakes into another mixing bowl. Add the brown sugar, and melted butter. Toss well, so that all the dried ingredients get nice and buttery.
Cover the berries with the buttery crumble. Bake for approximately 40 minutes until the crumble is golden brown and the fruit starts to bubble on the sides.
Serve with a ball of vanilla ice cream.