First Layer: Mix 1 cup flour, 1/2 cup margarine, and 1/4 cup walnuts. Press into a 9x13 inch pan. Bake 15 minutes at 350 degrees. Let cool.
Second Layer: Mix together 8 ounces cream cheese and 1 cup powdered sugar the add 1 carton cool whip and spread on cooled crust.
Third layer: Large package of instant chocolate pudding (or 1 small pkg. vanilla and 1 small package chocolate pudding). Make according to pie directions. Pour on top of second layer. Refrigerate for 1 hour till solid.
Fourth layer: Small carton cool whip and spread on top of third layer.