01 - Combine crushed cookies and melted butter in a bowl, mixing until evenly coated. Press the mixture firmly into the bottom of a 9x13 inch dish. Refrigerate while preparing the remaining layers.
02 - Combine blueberries, sugar, lemon juice, and water in a medium saucepan. Cook over medium heat until the berries burst and release their juices. Whisk cornstarch with a small splash of water to form a slurry, then stir into the berry mixture. Simmer until thickened, about 2 minutes. Remove from heat and cool completely.
03 - Beat cream cheese and powdered sugar together in a large bowl until smooth and free of lumps. Add lemon zest and lemon juice, mixing until fully incorporated. In a separate bowl, whip the cold heavy cream to stiff peaks. Gently fold the whipped cream into the lemon mixture in two additions, being careful not to deflate the volume.
04 - Spread half of the lemon cream evenly over the chilled cookie crust. Spoon half of the cooled blueberry sauce over the cream layer, spreading gently to avoid dragging. Repeat with the remaining lemon cream followed by the remaining blueberry sauce.
05 - Cover the dish tightly with plastic wrap and refrigerate for at least 4 hours, or overnight for the cleanest slices and best flavor development.
06 - Spread whipped cream over the top layer before serving. Garnish with fresh blueberries and a scattering of lemon zest. Slice into 12 portions and serve cold.