**Make the crust** In a mixing bowl, combine the crushed graham crackers (or cookies) with melted butter. Press the mixture firmly into an 8x8-inch baking dish to form an even layer. Chill in the freezer for 10 minutes to set.

**Prepare the creamy filling** In a separate bowl, beat the softened cream cheese, powdered sugar, vanilla extract, lemon juice, and optional lemon zest until smooth. Gently fold in the whipped topping until well combined.

**Assemble** Spread half of the lemon cream mixture over the chilled crust. Scatter blueberries evenly on top. Spoon the remaining lemon cream mixture over the berries, smoothing the surface with a spatula.

**Chill** Cover the dish and refrigerate for at least 3–4 hours, or until the dessert is set. For best results, chill overnight.

**Serve** Garnish with extra blueberries or a sprinkle of lemon zest before slicing. Enjoy cold.