1. Peel apples, and cut into 1/2-inch-thick wedges; toss with sugar and 1/2 cup flour.
2. Melt butter in a large skillet over medium-high heat; add apple mixture, and saute 15 to 20 minutes or until apples are tender. Remove from heat. Cool completely (about 1 hour).
3. Toss frozen blackberries with 1 Tbsp. flour, and stir into apple mixture. Use immediately.
Try This Twist! Cranberry-Apple Pie Filling: Omit blackberries and 1 Tbsp. flour. Reduce remaining flour from 1/2 cup to 1/3 cup. Stir in 1 cup sweetened dried cranberries just before removing apples from heat in Step 2.