I’d happily eat this every day! Don’t tell my doctor…

In a large bowl, whisk together the lemon pudding mix and milk for about 2 minutes, until it thickens.
Gently fold in the whipped topping until the mixture is well combined and creamy.
Add in the lemon juice and lemon zest, stirring gently to mix.
Arrange a single layer of graham crackers in the bottom of a 9×13 inch baking dish.
Spread half of the pudding mixture over the graham crackers.
Add another layer of graham crackers on top of the pudding mixture and then spread the remaining pudding mixture over this layer.
Finish with a final layer of graham crackers on top.
Cover and refrigerate the cake for at least 4 hours, or overnight, to allow the flavors to meld and the graham crackers to soften.

Slice and serve chilled.
Variations & Tips
For a fun twist, try making a mixed berry version by adding a layer of fresh berries between the pudding layers. If you prefer a little more texture, you can crush some graham crackers and sprinkle them on top just before serving for a bit of crunch. And if lemon isn’t your thing, you can easily swap out the lemon pudding for vanilla or cheesecake instant pudding mix for a different but equally delicious flavor.