Preheat your oven to 325°F (163°C). Grease a 9-inch springform pan with butter or non-stick spray.

Prepare the crust: In a medium bowl, mix graham cracker crumbs, melted butter, and granulated sugar. Press this mixture firmly into the bottom of the springform pan to create an even crust. Bake for 10 minutes or until golden, then remove from the oven and allow it to cool.

Make the filling: In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Gradually add powdered sugar and continue mixing until well combined, scraping the sides of the bowl as needed.

Add eggs and flavorings: Mix in vanilla extract, then add the eggs one at a time, mixing just until incorporated after each addition.

Add sour cream and blueberries: Fold in sour cream, fresh blueberries, cornstarch, lemon zest, and lemon juice until just combined. Be careful not to overmix the blueberries to keep them whole.

Assemble: Pour the cheesecake filling over the cooled crust and smooth the top with a spatula.

Bake: Bake for 50-60 minutes or until the center is set but still slightly jiggly. Turn off the oven and crack the door open, allowing the cheesecake to cool in the oven for an hour to prevent cracking.

Cool and refrigerate: After an hour, remove the cheesecake from the oven and let it cool completely at room temperature. Refrigerate for at least 4 hours or overnight until fully chilled and set.

Serve: Before serving, top with extra fresh blueberries for garnish. Carefully run a knife around the edge of the cheesecake before removing the springform pan for clean edges.