01 - Preheat oven to 350°F.
02 - In a medium bowl, combine flour, softened butter, and powdered sugar. Blend until the mixture resembles coarse crumbs. Press evenly into the bottom of a 9x13 inch baking dish.
03 - Bake for 18 to 20 minutes until the crust is lightly golden. Remove from the oven and allow to cool completely.
04 - Using an electric mixer, beat the cream cheese and powdered sugar until smooth and creamy. Gently fold in the whipped topping until combined. Spread the mixture evenly over the cooled crust.
05 - In a bowl, whisk the lemon pudding mixes with cold milk and lemon zest if using. Whisk vigorously for about 2 minutes until thickened. Let stand for 5 minutes to fully set, then spread evenly over the cream cheese layer.
06 - Spread the remaining whipped topping evenly over the lemon layer.
07 - Sprinkle lemon zest over the top for garnish if desired.
08 - Refrigerate for at least 2 hours, preferably 3 or more, until fully set. Slice into squares and serve chilled.