First layer: melt butter. Add flour and 1 cup pecans. Press in bottom of pan. Bake at 375 degrees for 15 minutes. Second layer: Cream together cream cheese, powdered sugar, 1 cup Cool Whip. Mix well. Spread over first layer. Third layer: Mix 2 packages pudding. Mix with milk and spread over second layer. Fourth Layer: top with Cool Whip on top and pecans and chill several hours.