Heat oven to 425 degrees F. In mixing bowl, combine pumpkin, sweetened condensed milk, egg, ¼ tsp. of the cinnamon, all the ginger, nutmeg and salt. Mix well. Turn into pie crust. Bake 15 minutes, remove pie. Reduce oven temperature to 350 degrees F. In small bowl, combine sugar, flour and remaining ½ tsp. cinnamon. Cut in margarine until crumbly. Stir in walnuts. Sprinkle walnut mixture evenly over pie. Bake 40 minutes or until knife inserted 1 inch from edge comes out clean. Cool. Garnish as desired. Refrigerate leftovers.
Makes 8 servings.