Mix flour, margine (or) butter and chopped pecans until crumbly (like you were making a pie crust). It will be sticky. Spread as best you can into a 9 x 13 pan. I use a fork to spread it out. Bake at 350 deg. for 20-25 minutes until light brown in color. Let cool completely.
Mix cream cheese, confectioners' sugar and cool whip with hand held mixer until well blended. Spread over top of cooled crust.
Mix 2 packages of instant vanilla pudding, and 3 cups whole milk with hand held mixer until it thickens. Pour over the cream cheese layer. Spread a layer of cool whip (desired thickness) over the pudding mixture. Sprinkle with remaining chopped pecans. Note: This recipe would also be good with sliced bananas mixed in with the pudding mixture.