Heat oven to 375°F. For filling, place apples in large bowl. Add sugar, cornstarch and cinnamon; sprinkle water over apples. Stir until ingredients are well combined and cornstarch is dissolved. Spoon into 8-inch square baking dish or other 2-quart baking dish. For topping, in medium bowl combine oats, flour blend, brown sugar and cinnamon; mix well. Cut in butter until mixture resembles coarse crumbs. Sprinkle evenly over apples. Bake 30 to 35 minutes until fruit is tender and topping is crisp. Serve warm.
Variation: Replace apples with 4 cups fresh or frozen, unsweetened sliced peaches, and 1 cup fresh or frozen, unsweetened raspberries (thaw fruit if frozen; do not drain). Omit cinnamon. Proceed as recipe directs.