01 - Preheat oven to 350°F. Lightly grease a 9x13 inch baking dish or line with parchment paper.
02 - In a medium bowl, combine all-purpose flour, softened butter, and powdered sugar. Blend until the mixture becomes crumbly and resembles coarse sand. Press the dough evenly into the bottom of the prepared baking dish, creating a uniform layer.
03 - Bake for 18 to 20 minutes, or until the crust is lightly golden around the edges. Remove from the oven and allow to cool completely before adding subsequent layers.
04 - Using an electric mixer, beat the softened cream cheese and powdered sugar together on medium speed until completely smooth and free of lumps. Gently fold in the thawed whipped topping until evenly combined. Spread the mixture in a smooth, even layer over the fully cooled crust.
05 - In a mixing bowl, whisk together both packages of instant lemon pudding mix and cold milk for approximately 2 minutes until the mixture thickens. Add lemon zest if desired for enhanced citrus flavor. Allow the pudding to rest for 5 minutes to fully set, then spread evenly over the cream cheese layer.
06 - Spread the remaining whipped topping evenly over the lemon pudding layer, smoothing the surface with a spatula.
07 - Sprinkle lemon zest over the top as a garnish for a bright, citrusy finish.
08 - Refrigerate for at least 2 hours, preferably 3 or more, to allow all layers to set firmly. Slice into squares and serve chilled.