Add butter and mix by hand to cut butter into dry ingredients. Stir in walnuts. Sprinkle oat mixture over fruit in casserole dish. Bake crisp at 325 degrees until fruits start bubbling and topping is lightly browned, about 45 minutes. Makes 2 servings.
Maple sugar is a dry version of maple syrup.
It's available in many natural foods stores. If you can't find it, use 4 tbsp.