1 Preheat oven to 350°F. For the Mixed Berry Filling, toss berries with granulated sugar, lemon juice and vanilla in large bowl. Sprinkle with cornstarch; toss to coat well. Spoon into lightly greased 8- or 9-inch square baking dish.
2 For the Streusel Topping, mix flour, oats, brown sugar, cinnamon and ginger in medium bowl. Cut in butter with pastry blender or 2 knives until coarse crumbs form. Sprinkle evenly over fruit.
3 Bake 40 to 45 minutes or until fruit is tender and topping is golden brown. Serve warm with ice cream or whipped cream, if desired.