Cut butter into flour with a pastry blender or fork until mixture resembles coarse meal. Stir in pecans. Press mixture onto bottom of a 13- x 9-inch pan.
Bake at 350° for 15 minutes or until lightly browned. Cool.
Beat cream cheese, powdered sugar, and 1 cup whipped topping at medium speed with an electric mixer until smooth. Spread mixture over prepared crust.
Whisk together pudding mix and milk 2 minutes or until smooth. Spread over cream cheese mixture. Chill 10 minutes. Spread remaining whipped topping over pudding mixture. Cover and chill at least 1 hour. Cut into squares.
As written, this recipe is just so-so. My family does not care for the instant chocolate pudding flavor...so I wound up altering the recipe to the point that it's almost a new recipe. Lol. This, IMHO, takes it up to 5 stars: add about 1/8 tsp of cinnamon and .25 c of sugar to the pudding mix. Then mix 1 can of condensed milk with 1.5 cups of water and .5 cup of whole milk and 1 tsp of vanilla, then mix into the pudding mix. It didn't seem to have enough crust, so I used 1.5 cups of flour and 1.5 sticks of butter and decreased the pecans to .5 cup. I also did .75 cups of powdered sugar to the cream cheese mixture.