Line an 8x8-inch baking dish with parchment paper, leaving an overhang on two sides to make the bars easy to lift out later.

In a medium bowl, combine the crushed vanilla wafer crumbs, melted butter, and optional granulated sugar. Mix until the crumbs are evenly moistened.

Press the crumb mixture firmly into an even layer in the bottom of the prepared baking dish. Use the bottom of a measuring cup or glass to compact the crust. Refrigerate while preparing the filling.

In a large mixing bowl, beat the softened cream cheese for 1 to 2 minutes, until completely smooth.

Add powdered sugar, vanilla extract, and lemon juice. Beat until creamy and well combined, scraping down the bowl as needed.

In a separate chilled bowl, whip the cold heavy cream until stiff peaks form.

Fold the whipped cream gently into the cream cheese mixture in two additions. Fold only until smooth and no white streaks remain.

Spread the cream cheese filling evenly over the chilled vanilla wafer crust. Smooth the top with an offset spatula or the back of a spoon.

Spoon the blueberry pie filling over the cream cheese layer. Spread gently into an even layer. Sprinkle with optional lemon zest.

Cover the dish and refrigerate for at least 4 hours, preferably overnight, until the dessert is firm.

Lift the chilled dessert out of the pan using the parchment paper. Slice into 12 bars with a sharp knife, wiping the blade clean between cuts. Garnish with fresh blueberries or crushed vanilla wafers if desired. Serve cold.