PREPARATION:

1. Preheat oven to 425°F. Place baking sheet in oven while preheating.
2. Combine, apples, lemon juice and vanilla in large bowl; set aside.
3. Combine brown sugar, 3 tablespoons flour, cinnamon and nutmeg in medium bowl; blend thoroughly. Add brown sugar mixture to apple mixture; toss to coat. Spoon into pie crust; set aside.
4. Heat 10-inch nonstick skillet over medium-high heat until very hot. Add nuts; cook 2 minutes, stirring constantly with wooden spoon until lightly browned and fragrant. Remove from heat; set aside.
5. Combine remaining 1/3 cup flour and granulated sugar in small bowl. Cut in margarine using pastry blender or two knives until mixture resembles coarse crumbs; sprinkle evenly over pie. Top with walnuts.
6. Bake 35 to 40 minutes or until bubbly and apples are tender in center.