Layer #1
Mix together flour, chopped nuts, and butter. Press on bottom of 9×13 pan. Bake 12 to 15 minutes at 350 degrees.
LAYER #2:
Combine cream cheese, powdered sugar, 1 c. Cool Whip. Put on first layer when it is cool.
LAYER #3:
Whisk together chocolate pudding and milk. Put on top of second layer.
LAYER #4:
Cover third layer with remaining Cool Whip and sprinkle with grated Hershey bar.
Refrigerate for a few hours before serving.