Melt butter; stir in flour and 1 c of the nuts. Continue stirring until a thick paste is formed, with no flour lumps. Press into bottom of a 13x10 baking pan and bake 15 min at 375F. Cool. Prepare first layer of filling by combining cream cheese, sugar, and 1 c whipped topping. Beat with electric mixer at med speed for 2-3 min. Spoon into cooled crust, then smooth with spatula. Combine pudding and milk in the mixing bowl used for the first filling. Beat well, then pour over the cream cheese layer. As soon as the chocolate layer firms up a bit, spoon on more whipped topping, smoothing and adding until there is an additional 1/2" layer above the chocolate. Sprinkle with remaining pecans and chill for at least 3 hours. From the Pipe Dream Restaurant, Willington, CT