Preheat the oven to 400 degrees. Butter a pie dish, or small casserole.
In a bowl, stir together the fruit (defrosted, if frozen), sugar, and cornstarch. Pour this into the pie dish in an even layer.
For the Crumble Topping: In a large bowl, stir together the flour, sugar, oats, and coconut. Using a pastry cutter, cut the butter into the flour mixture. Sprinkle this crumble topping on top of the blueberries, distributing it evenly. Bake for thirty minutes. Serve warm and topped with ice cream.