Walnut Pumpkin Pie

INGREDIENTS
1 (9 inch) prepared graham cracker crust
2 cups pumpkin puree
1 (14 ounce) can sweetened condensed milk
1 egg
1 1/4 teaspoons ground cinnamon
1/2 teaspoon ground ginger
1/2 teaspoon ground nutmeg
1/2 teaspoon salt
1/4 cup packed brown sugar
2 tablespoons all-purpose flour
2 tablespoons butter
3/4 cup chopped walnuts

DIRECTIONS
Preheat oven to 425 degrees F (220 degrees C).
In a mixing bowl, combine the pumpkin, condensed milk, egg, 3/4 teaspoon cinnamon, ginger, nutmeg and salt. Pour batter into the pie crust.
Bake at 425 degrees F (220 degrees C) for 15 minutes. Reduce oven temperature to 350 degrees F (175 degrees C).
In a small bowl, combine brown sugar, flour, and remaining 1/2 teaspoon cinnamon. Cut in the butter or margarine until the mixture is crumbly. Stir in walnuts. Sprinkle mixture evenly over the pie. Bake pie for 40 minutes or until a knife inserted one inch from the edge comes out clean.