Prepare the filling. Position rack in center of oven and preheat to 400°F. Mix all ingredients in 13x9x2-inch glass baking dish. Bake 15 minutes.
Prepare the topping. Mix flour, 4 tablespoons sugar, baking powder and salt in large bowl. Using fingertips, rub in butter and shortening until mixture resembles coarse meal. Add egg and buttermilk; stir until batter forms.
Remove fruit from oven. Spoon batter over hot filling in 12 mounds, spacing evenly. Sprinkle with 2 tablespoons sugar. Bake until juices thicken and topping is golden, about 30 minutes. Cool on rack at least 15 minutes.
Serve warm with vanilla ice cream.