Preheat oven to 375° F.
In a large bowl, combine all ingredients for the filling and mix well. Strawberries can be sliced, other berries can be left whole. Add to a 9x9 baking dish.
In another bowl, add all ingredients for the topping and mix with a pastry cutter, a fork, or your hands. Work the butter into the dry ingredients to form a crumb-like consistency. Sprinkle the topping evenly over the filling.
Bake at 375° for 40 minutes. Allow to cool slightly, and serve with vanilla ice cream.
