Add the softened cream cheese to a large mixing bowl and beat with a hand mixer until smooth, fluffy, and light.

Add the lemon pudding powder, vanilla extract, and fresh lemon juice. Mix again until the filling becomes smooth and evenly yellow.

Slowly pour in the milk while mixing. Continue until the mixture is mostly smooth with very few lumps.

Fold in the Cool Whip gently with a spatula until the filling is combined.

Spread about 1/2 cup of the lemon pudding mixture across the bottom of a 9x13 baking dish.

Add one even layer of graham crackers over the pudding layer. Break crackers as needed so they fit the dish.

Spread one-third of the remaining lemon pudding mixture over the graham crackers.

Repeat the layers: graham crackers, pudding mixture, graham crackers, then pudding mixture again.

Chill the cake by freezing it for 4 hours or refrigerating it overnight.

Before serving, let it sit at room temperature for 15 to 20 minutes if frozen, then top with lemon zest, raspberries, sliced lemons, blueberries, graham cracker crumbs, or whipped cream if desired.