Prepare for Baking:
Preheat your oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, allowing the edges to hang over for easy removal.
Make the Crust:
In a bowl, mix graham cracker crumbs, melted butter, and sugar until evenly combined.
Press the mixture firmly into the bottom of the prepared pan to form an even crust.
Bake for 10 minutes, then set aside to cool.
Prepare the Cheesecake Filling:
In a large mixing bowl, beat the cream cheese and sugar until smooth.
Add the eggs, one at a time, mixing well after each addition.
Mix in the vanilla extract and sour cream until fully combined.
Assemble and Bake:
Pour the cheesecake filling over the cooled crust, spreading it evenly.
Bake for 30–35 minutes, or until the edges are set and the center is slightly jiggly.
Let the bars cool to room temperature, then refrigerate for at least 4 hours or overnight.
Make the Blueberry Topping:
In a saucepan over medium heat, combine blueberries, sugar, cornstarch, water, and lemon juice.
Cook, stirring frequently, until the mixture thickens and the blueberries break down slightly, about 5–7 minutes.
Let the topping cool completely before spreading it over the chilled cheesecake.
Slice and Serve:
Using the parchment paper overhang, lift the bars out of the pan.
Slice into squares or rectangles and serve chilled.