Preheat oven to 350°F Butter 8x8x2 1/2-inch square baking dish.
Toss fruit, brown sugar and flour in large bowl to combine. Transfer to prepared baking dish. Bake fruit until juices bubble, stirring occasionally, about 40 minutes. Bake without stirring another 5 minutes. Remove from oven.
Increase oven temperature to 375°F
Meanwhile, stir together oats, spices, salt, and 2 tablespoons brown sugar in a bowl until combined. Rub butter into oat mixture until evenly distributed.
Sprinkle topping over fruit and bake until topping is golden, 25 to 30 minutes more. Transfer to a rack to cool at least 10 minutes. Serve warm or at room temperature.