HEAT oven to 325ºF.
RESERVE 1 Tbsp. nuts. Mix remaining nuts with butter, flour and granulated sugar until well blended; press onto bottom of 13x9-inch pan. Bake 15 min.; cool completely.
BEAT cream cheese and icing sugar in medium bowl with whisk until well blended. Stir in 2 cups Cool Whip; spread over crust.
BEAT pudding mixes and milk with whisk 3 min. Pour over cream cheese layer; let stand 5 min. or until thickened. Cover with remaining Cool Whip. Refrigerate 4 hours. Sprinkle with remaining nuts just before serving.