Combine first 4 ingredients in a bowl and beat with an electric mixer until smooth. With mixer on low speed, gradually beat in flour until just crumbly. Set topping aside. Preheat oven to 425°F. Combine sugar and cornstarch in a large bowl. Gently stir in cherries, berries, and lemon juice. Turn filling into frozen pie shell. Sprinkle topping evenly over top of pie. Place pie on a cookie sheet and bake 15 minutes. Reduce oven temperature to 375°F. Bake 45–50 minutes longer, or until filling is bubbly in center. Let cool completely on a wire rack

Recipe courtesy Meals For You. Visit http://www.MealsForYou.com.