1/2 cup chilled unsalted butter, cut into small pieces
4 large Granny Smith apples, peeled, cut into pieces
1 16-ounce can whole cranberry sauce
3/4 cup sugar
1 teaspoon cornstarch
1 9-inch deep dish frozen pie shell, unthawed
Preheat oven to 350 degrees.
Mix first 4 ingredients. Add butter, mix until mixture resembles coarse cornmeal.
Place baking sheet in oven. Toss apples, cranberry sauce, sugar and cornstarch until well blended.
Transfer apple-cranberry filling to frozen pie shell, mounding in centre.
Sprinkle topping over pie. Set pie on baking sheet in oven. Bake until apples are tender, juices bubble thickly and crust is golden, about 1 hour 10 minutes.
Serve warm with whipped cream or vanilla ice cream.