In a food processor, grind graham crackers into fine crumbs. Alternatively, place them in a zip-top bag and crush with a rolling pin. Transfer crumbs to a bowl, stir in sugar, then mix in melted butter. Press the mixture into the bottom of the prepared pan.

Bake the crust for 8 minutes, then remove from the oven and let cool for a few minutes while preparing the filling.

Beat cream cheese in a mixer on medium speed for 1 minute until smooth. Add egg, sugar, lemon zest, lemon juice, and vanilla extract, and beat on medium speed for about 3 minutes until fully combined and creamy. Gently fold in blueberries.

Pour the cream cheese mixture over the slightly cooled crust and spread evenly.

Bake for 30–35 minutes, or until the cheesecake has set and the edges are lightly browned. The bars will puff up, then settle as they cool.

Allow the bars to cool on a wire rack for 30 minutes at room temperature, then refrigerate for at least 3 hours until fully chilled.

Once chilled, lift the bars out of the pan using the parchment paper and cut into squares.