Prepare the Crust:

Preheat your oven to 350°F (175°C). Line the bottom of a 9-inch springform pan with parchment paper and wrap the outside tightly with heavy-duty aluminum foil to waterproof it.

In a medium bowl, combine the graham cracker crumbs, sugar, and melted butter until the mixture resembles wet sand.

Press the crumb mixture firmly and evenly into the bottom and slightly up the sides of your prepared springform pan.

Bake the crust for 10 minutes. Remove from the oven and set aside to cool slightly.

Reduce the oven temperature to 300°F (148°C).

Prepare the Filling:

In a large mixing bowl or stand mixer, beat the room-temperature cream cheese, sugar, and flour on low speed until completely smooth and combined. Scrape down the sides and bottom of the bowl to prevent lumps.

Add the sour cream and vanilla extract, mixing on low speed until seamlessly incorporated.

Add the eggs one at a time, mixing on low speed just until the yellow of the yolk disappears after each addition. Do not overmix.

Gently use a silicone spatula to fold the 1 ¾ cups of blueberries into the batter.

Pour the finished cheesecake batter evenly over the pre-baked graham cracker crust and smooth the top.

Bake the Cheesecake:

Place your foil-wrapped springform pan inside a larger roasting pan. Pour warm water into the roasting pan until it reaches halfway up the sides of the springform pan.

Bake at 300°F (148°C) for 1 hour and 20 to 25 minutes. The edges should be set, but the center should still have a slight jiggle to it.

Turn off the oven completely. Leave the cheesecake inside with the oven door tightly closed for exactly 30 minutes.

After 30 minutes, crack the oven door open slightly and leave the cheesecake inside for another 30 minutes to cool gradually.

Remove the cheesecake from the oven and carefully lift it out of the water bath. Remove the foil wrapping and place the pan in the refrigerator to chill until completely cold and fully set (at least 6 hours, preferably overnight).

Prepare the Blueberry Sauce:

In a small bowl, whisk together 1 tablespoon of water and the cornstarch to create a slurry. Set aside.

In a medium saucepan, combine the sugar, the remaining ½ cup of water, and the lemon juice. Stir over medium heat until the sugar is fully dissolved.

Add the 2 cups of blueberries to the saucepan. Cook until the berries soften and begin to release their vibrant juices.

Once the mixture resembles a loose, bubbling sauce, stir in the prepared cornstarch slurry.

Continue cooking and stirring constantly until the sauce visibly thickens and coats the back of a metal spoon.

Remove the pan from the heat and transfer the sauce to a heat-proof container. Refrigerate until completely cool.

Assemble and Serve:

Once both the cheesecake and the sauce are completely chilled, carefully release the outer ring of the springform pan.

Transfer the cheesecake to a serving platter. Spoon the chilled blueberry sauce over the top, slice cleanly, and serve immediately.