Preheat your oven to 350°F (175°C). In a mixing bowl, combine all-purpose flour, granulated sugar, and chopped nuts with softened butter until it resembles coarse crumbs. Press this mixture firmly into the bottom of a greased 9x13 inch baking dish. Bake for about 15 minutes or until lightly golden brown; then allow it to cool completely.
In another bowl, beat together softened cream cheese and granulated sugar until smooth and creamy. Add in the zest and juice of one lemon to enhance that fresh flavor profile. Spread this delicious mixture evenly over the cooled crust layer, ensuring it's well-distributed.
In a separate bowl, whisk together both packages of instant lemon pudding with cold milk until it thickens nicely—this should take about two minutes. Once thickened, gently fold in half of the whipped topping until combined perfectly for a light texture.
Spread the pudding mixture over the cream cheese layer carefully; then top it off with remaining whipped topping for an airy finish. Garnish with additional lemon zest and place some lemon slices on top for an attractive presentation.
Allow your assembled Lemon Lush Cake to chill in the refrigerator for at least two hours before serving; this helps all layers set beautifully together, enhancing those lovely flavors! When ready to serve, cut into squares and enjoy this refreshing dessert!