Preheat your oven to 350°F (175°C) and line a 9x9 inch baking pan with parchment paper, leaving some overhang for easy removal later.
In a mixing bowl, combine the graham cracker crumbs, melted butter, and 2 tablespoons of sugar. Mix until the crumbs are well-coated with butter.
Press the crumb mixture firmly into the bottom of the prepared baking pan to create an even base. Bake in the preheated oven for 10 minutes, then remove and allow to cool slightly.
In a large bowl, using an electric mixer, beat the softened cream cheese until smooth. Gradually add 1 cup of sugar, mixing until well incorporated.
Add the eggs one at a time, blending well after each addition. Stir in the vanilla extract, lemon zest, and lemon juice until the mixture is smooth again.
In a small bowl, toss the fresh blueberries with cornstarch to coat them lightly. This will help prevent them from sinking in the batter. Gently fold the blueberries into the cheesecake mixture.
Pour the cheesecake mixture over the cooled crust in the baking pan. Smooth the top with a spatula.
Bake for 25-30 minutes, or until the center is slightly set and just begins to puff up. It should still have a slight jiggle.
Allow the cheesecake bars to cool at room temperature for about an hour, then refrigerate for at least 3-4 hours (or overnight for best results) to firm up.
Once set, lift the cheesecake out of the pan using the parchment overhang. Cut into squares or bars.
Notes
Serve chilled with a dusting of powdered sugar and additional blueberries for garnish.