Layer one: Mix flour, butter, and ½ cup pecans. Press into a greased 9×9 pan. Bake for 15 minutes at 350°F, then remove and let cool.
Note: If you are using a 9×13 pan, or would like a thicker crust, add an additional ½ cup flour, ¼ cup butter, and ¼ cup chopped pecans.

Blend cream cheese and powdered sugar, fold in 1 cup of the whipped topping, then spread over cooled crust.

Layer three: Mix milk, pudding mix, canned pumpkin, pumpkin spice, and 1 cup whipped topping until smooth. Spread over top of layer 2.

Layer four: Spread remaining 1 cup of whipped topping and sprinkle with pecans.
Let chill for 3 hours or until set. Serve chilled.