Preheat oven to 325°F (160°C). Line an 8×8-inch baking pan with parchment paper.

In a bowl, mix graham cracker crumbs, sugar, and melted butter. Press mixture firmly into the bottom of the pan to form the crust.

Bake crust for 10 minutes, then set aside to cool slightly.

In a large bowl, beat cream cheese until smooth. Add sugar and flour; mix until well combined.

Add eggs, one at a time, then mix in sour cream, lemon juice, and zest until smooth.

Fold in the blueberries gently.

Pour filling over the crust and smooth the top.

Bake for 35–40 minutes, or until the center is set and edges are slightly golden.

Let cool completely, then refrigerate for at least 3 hours before slicing into bars.