Preheat your oven to 375°F. Place your springform pan in the center of two large sheets of heavy-duty aluminum foil and pull the foil up tightly around the outside of the pan, sealing it completely. Lightly spray the inside of the pan with baker's spray and set aside.

Combine the graham cracker crumbs, sugar, and melted butter in a medium bowl and stir until the mixture looks like wet sand and holds together when you pinch it. If it feels too dry, add more melted butter one tablespoon at a time. Transfer the mixture to the prepared pan and press it firmly and evenly into the bottom and about three quarters of the way up the sides.

Bake for 10 minutes, then remove from the oven and set aside to cool. Lower the oven temperature to 325°F and start bringing 6 cups of water to a boil for the water bath.

Add the softened cream cheese and sugar to the bowl of a stand mixer fitted with the paddle attachment. Beat on medium-low speed for 2 to 3 minutes until the mixture is completely smooth, scraping down the sides of the bowl and the paddle attachment as needed.

With the mixer still on low, add the eggs one at a time, waiting until each one is fully incorporated before adding the next. Scrape down the bowl as needed.

Add the sour cream, heavy cream, lemon zest, lemon juice, and vanilla extract and mix on low until the batter is smooth and well combined. Remove the bowl from the mixer and give the batter a final stir by hand to make sure everything is evenly mixed.

In a small bowl, toss the blueberries with the flour until lightly coated. Gently fold the coated blueberries into the batter, being careful not to break them. Pour the batter into the cooled crust and smooth the top into an even layer.

Set the springform pan inside a large roasting pan and place it on the center rack of the oven. Carefully pour the boiling water into the roasting pan until it comes about 1 inch up the side of the springform pan, using between 4 and 6 cups depending on the size of your pan.

Bake for 1 hour and 20 to 30 minutes. The cheesecake is ready when the edges are just set and the center still has a gentle jiggle when you carefully move the pan.

Turn off the oven and prop the door open about an inch using the handle of a wooden spoon. Leave the cheesecake to cool undisturbed in the oven for 1 hour.

Remove the roasting pan from the oven and lift the springform pan out. Carefully remove the foil and allow the cheesecake to finish cooling on the counter for 1 hour. Once cooled, refrigerate for at least 8 hours or overnight.

While the cheesecake is baking, add the blueberries, sugar, water, lemon juice, and vanilla to a medium saucepan over medium heat. Stir gently as the mixture warms, allowing the sugar to dissolve and the blueberries to soften. Take care not to break the blueberries as you stir.

In a small bowl, whisk the cornstarch together with the remaining 2 tablespoons of water until no lumps remain. Once the blueberry mixture reaches a steady simmer, stir in the cornstarch slurry and cook for another 30 seconds to 1 minute until the sauce is thick enough to coat the back of a spoon.

Remove from the heat and transfer to a bowl. Press a sheet of plastic wrap directly onto the surface of the sauce to prevent a skin from forming. Allow to cool, then refrigerate until ready to use.

Once the cheesecake has chilled completely, spoon the blueberry sauce over the top, leaving a half inch to one inch border around the edge. Slice and enjoy.