For the filling: Preheat the oven to 350 degrees F. Spray a 2 1/2-quart baking dish with nonstick cooking spray.
Toss together the fruit, sugar, cornstarch, cinnamon and salt in a large bowl and pour into the prepared baking dish.
For the topping: Whisk together the flour, milk, melted butter, sugar, baking powder and salt. Stir just until mixed together, being careful not to over-stir. Pour the topping over the top of the filling.
Bake until the topping is golden brown and the filling is bubbling, about 1 hour.
Let cool slight, and serve warm with vanilla ice cream.