1. Preheat oven to 375°. Stir together first 3 ingredients, 1/4 cup flour, and 1/4 tsp. salt until well blended.
2. Cut butter into remaining 1/2 cup flour with a pastry blender or fork until mixture resembles small peas. Stir in brown sugar, oats, and remaining 1/4 tsp. salt.
3. Fit piecrust into a 9-inch pie plate according to package directions; fold edges under, and crimp. Place apple mixture in piecrust, and top with brown sugar mixture, pressing gently to adhere. Shield edges of crust with aluminum foil. Place pie on a foil-lined baking sheet.
4. Bake at 375° for 25 minutes. Remove foil from crust, and bake 25 minutes or until golden brown. Sprinkle with pecans, and bake 5 to 7 minutes or until pecans are toasted. Let pie stand 30 minutes to 2 hours before serving. Serve with caramel topping and ice cream.