Pistachio Surprise

1-1/2 c. all-purpose flour
1/2 c. margarine
1/2 c. chopped walnuts
8-oz. pkg. cream cheese, softened
1 c. powdered sugar
8-oz. container frozen whipped topping, thawed and divided
2 3-1/2 oz. pkgs. instant pistachio pudding mix
3 c. milk
Optional: chopped walnuts

Mix flour, margarine and walnuts together. Press into a greased 13"x9" baking pan. Bake at 350 degrees for 18 minutes; cool. Combine cream cheese, powdered sugar and half of whipped topping. Whip together until smooth; spread on cooled crust. Mix together pudding mix, milk and remaining whipped topping until smooth. Spread over cream cheese mixture. Sprinkle with additional walnuts, if desired. Chill for several hours before serving. Serves 12 to 16.