Heat oven to 375°F. Make pie crusts as directed on box for Two-Crust Pie, using 9-inch glass pie plate.
In large bowl, combine apples and blackberries. In small bowl, combine brown sugar, cornstarch, cinnamon and nutmeg. Stir into fruit; toss to coat. Spoon into crust-lined pie plate.
Top with second crust and flute; cut slits in pastry. Cover crust edge with strips of foil to prevent excessive browning.
Place pie on middle oven rack; place sheet of foil on rack below pie in case of spillover. Bake 50 minutes. Remove foil; bake an additional 15 to 20 minutes or until golden brown. Cool at least 3 hours before serving.