01 - Preheat oven to 350°F.
02 - In a medium bowl, blend flour, softened butter, and powdered sugar until crumbly. Press evenly into the bottom of a 9x13 inch baking dish.
03 - Bake crust for 18 to 20 minutes, or until lightly golden. Allow to cool completely before proceeding.
04 - With an electric mixer, beat cream cheese and powdered sugar until smooth. Fold in whipped topping. Spread mixture evenly over the cooled crust.
05 - Whisk together lemon pudding mixes and cold milk (and lemon zest, if using) for 2 minutes until thickened. Let sit for 5 minutes to fully set, then spread evenly over the cream cheese layer.
06 - Spread remaining whipped topping evenly over the lemon layer.
07 - Garnish with lemon zest if desired.
08 - Chill at least 2 hours, preferably 3 or more, before slicing and serving.