In a small saucepan, combine blueberries, sugar and lemon juice. Cook and stir over medium heat for 5 minutes or until the berries are softened. Mash some as you stir.

Combine cornstarch and water in a bowl until smooth. Stir into blueberry mixture. Bring to a boil and stir for 2 minutes or until thickened. Remove from heat and set aside to cool.

In a medium bowl, combine graham cracker crumbs, sugar, salt, and melted butter. Stir well to combine. Spread crumb crust mixture into the springform pan evenly and half way up the sides. Press it firmly to compact it together.

In the bowl of a stand mixer fitted with the whisk attachment, beat softened cream cheese and sour cream until smooth.

Pour in sugar and vanilla and beat until smooth, scraping down the sides and bottom of bowl as needed.

Add egg and beat until smooth. Stir in flour and mix until just combined.

Quickly stir in lemon juice and zest, mixing just until it's incorporated into batter.

Pour filling into prepared crust, and spread top smooth if needed.

Spoon a few dollops of blueberry mixture on top of unbaked cheesecake. Use a skewer or knife to swirl mixture as much or as little as you'd like.

Place cheesecake pan on a baking sheet and move to oven. Bake cheesecake about 90 minutes or until almost set.

Remove cheesecake from oven and let cool in pan 10 minutes.

Place springform pan in refrigerator to chill 2 hours or overnight.

After its done chilling, remove sides of pan and slice into 4 large or 6 small pieces. You can use a long knife dipped in very hot water to slice the cheesecake.