Preheat oven to 400. In 23 cm pie pan, combine brown sugar, margarine and walnuts. Carefully place one crust on top of sugar/nut mixture; trim even with edge of pie pan. Combine remaining ingredients and put into pie crust. Cover with remaining pie crust; trim even with edge of pie pan. Fold crust edge inward toward center of pie; seal edges with water. Prick top of crust to vent; place on foil-covered baking sheet. Bake 40-45 minutes or until golden brown. Let stand 2 minutes. Carefully run knife tip around plate to loosen pie. Invert onto serving platter. Serve warm with ice cream of whipped cream. ----