01 - Combine the crushed cookies and melted butter in a bowl, mixing until evenly moistened. Press the mixture firmly into the bottom of a 9x13 inch dish. Refrigerate while preparing the remaining layers.
02 - Add blueberries, sugar, lemon juice, and water to a saucepan and cook over medium heat until the berries burst and release their juices. Whisk the cornstarch with a small splash of water to form a slurry, then stir it into the berry mixture. Simmer until thickened, about 2 minutes. Remove from heat and cool completely.
03 - Beat the cream cheese and powdered sugar together in a large bowl until smooth and free of lumps. Incorporate the lemon zest and juice, mixing until well blended. In a separate bowl, whip the cold heavy cream to stiff peaks. Gently fold the whipped cream into the lemon mixture until just combined, being careful not to deflate the cream.
04 - Spread half of the lemon cream evenly over the chilled cookie crust. Spoon half of the cooled blueberry sauce over the cream layer and spread gently. Repeat with the remaining lemon cream, then finish with the remaining blueberry sauce.
05 - Cover the dish tightly and refrigerate for at least 4 hours, or overnight for the cleanest slices and best flavor development.
06 - Spread the whipped cream over the top layer just before serving. Finish with fresh blueberries and a sprinkle of lemon zest.