HEAT oven to 400 degrees F. Spray an 8-inch square (2-quart) baking dish with no-stick cooking spray. Lightly spoon flour into measuring cup; level off. Combine flour, 1/4 cup sugar and baking powder in medium bowl; mix well. CUT in butter with pastry blender or fork until mixture is crumbly. Add egg whites and milk; stir until well blended. Set aside. COMBINE all fruit mixture ingredients in large bowl; mix well. Spoon into prepared baking dish. Spoon topping evenly over fruit mixture. BAKE 45 to 50 minutes or until topping is golden brown. Serve warm with ice cream.