Preheat your oven to 350°F (175°C). In a mixing bowl, combine 2 cups of all-purpose flour with 1 cup of softened butter. Mix until the mixture resembles coarse crumbs. Press this mixture into the bottom of your greased 9x13-inch baking dish.
Bake the crust in the preheated oven for 15-20 minutes or until it’s lightly golden. Once done, remove it from the oven and let it cool completely.
In a clean mixing bowl, beat together the two 8-ounce packages of cream cheese and 1 cup of granulated sugar until smooth and creamy. Spread this mixture evenly over the cooled crust.
In another bowl, whisk together 3 cups of milk and the two boxes of instant lemon pudding. Continue whisking until the mixture thickens, which usually takes about 2 minutes. Once thickened, gently fold in 12 ounces of Cool Whip until combined.
Pour the lemon filling over the cream cheese layer in the baking dish, spreading it evenly to cover the surface.
Cover the dessert with plastic wrap and refrigerate for at least 4 hours, though overnight is best to allow the flavors to meld beautifully. When ready to serve, slice into squares and enjoy the refreshing burst of lemon!