Preheat oven to 350F.  Spray a 9x13 inch baking dish with cooking spray.

Add 2 cups pecans to a food processor or nut chopper. Save about 1/2 cup chopped pecans for sprinkling on top.

Add all crust ingredients and mix well until combined. Press crust mixture into prepared baking sheet. Place baking dish in the oven and bake 20 minutes. Cool completely.

Add cream cheese to a bowl and mix until softened. Add powdered sugar and continue mixing until smooth. Fold in whipped topping. Set aside.

Prepare pudding as directed on pkg, but use 2 1/2 cups of milk for a firmer pudding. Add canned pumpkin, pumpkin pie spice and whipped topping. Fold everything in until well combined. 

When crust has cooled completely, spread cream cheese mixture evenly over crust. Spread pumpkin mixture evenly over cream cheese. Top with whipped topping and then sprinkle with remaining chopped pecans. Chill for at least 3 hours to set before serving.