01 - Combine crushed vanilla wafers or graham crackers with melted butter in a bowl until the texture resembles wet sand. Evenly press the mixture into the base of a 9x13-inch rectangular baking dish using a spatula or the back of a measuring cup. Transfer the pan to the freezer to firm the crust while preparing the next components.
02 - In a mixing bowl, beat the softened cream cheese with an electric mixer until completely smooth. Incorporate powdered sugar, fresh lemon juice, and lemon zest; blend until homogeneous. In a separate bowl, whip the cold heavy cream to stiff peaks, then gently fold it into the lemon cream base. Spread this mixture carefully over the chilled crust using a spatula.
03 - In a saucepan set over medium heat, combine blueberries, granulated sugar, and lemon juice. Stir until the berries begin to burst and release juice, approximately 4 to 5 minutes. Introduce the cornstarch slurry and continue stirring until the mixture thickens, about 2 to 3 minutes. Remove from heat and cool completely before assembling.
04 - Once cooled, carefully spread the blueberry mixture evenly over the lemon cream layer. Use a spatula to smooth the surface if needed.
05 - Whip the cold heavy cream with powdered sugar and vanilla extract until stiff peaks form. Spread the whipped topping over the blueberry layer, ensuring an even finish.
06 - Sprinkle freshly grated lemon zest and, if desired, additional blueberries on the surface for decorative effect.
07 - Refrigerate for at least 4 hours, ideally overnight, to allow the layers to set fully before slicing and portioning.