1. Prepare the lemon cream layer
In a large mixing bowl, beat the softened cream cheese and powdered sugar until smooth. Add the lemon zest and juice, and mix again until fully incorporated.

2. Make the whipped cream
In a separate bowl, whip the heavy cream and vanilla extract until stiff peaks form. Gently fold the whipped cream into the lemon-cream cheese mixture until well combined.

3. Layer the cake
In a 9×5-inch loaf pan lined with plastic wrap (leaving overhang for easy removal), spread a thin layer of the lemon cream on the bottom.

4. Add graham crackers
Layer graham crackers over the cream, breaking them to fit if necessary. Spread another layer of cream over the crackers, then top with blueberries.

5. Repeat
Continue layering cream, crackers, and blueberries until you reach the top of the pan, finishing with a layer of cream.

6. Chill
Cover the cake with plastic wrap and refrigerate for at least 6 hours, preferably overnight, to let the layers set and the crackers soften.

7. Serve
Use the plastic wrap overhang to lift the cake from the pan. Slice and garnish with extra blueberries, lemon zest, or lemon slices before serving.