In a medium pan, combine blueberries and sugar. Whisk together water and corn starch and add to the pan. Cook over medium heat, stirring often, until bubbly and thickened, about 5-8 minutes. Set aside to cool to room temperature (the fridge makes this go much quicker)

Preheat oven to 325 degrees F and line a 9" Springform pan with parchment paper (pinch it in between the bottom and the sides) Stir together graham cracker crumbs, butter and sugar and press into the pan and about 1/2" up the sides.

Bake for 10-12 minutes, just until dry. Remove to cool and reduce oven temperature to 275 degrees F.

In a large bowl, beat cream cheese with an electric mixer until smooth.

Add sour cream, sugar, eggs and vanilla and beat until smooth.

Add Lemon Zest

Pour half of the filling into another bowl. Stir in ½ cup blueberry sauce.

Pour blueberry cheesecake filling into prepared crust.

Carefully pour plain cheesecake filling over the blueberry, drizzling back and forth to cover in an even layer. Spread to smooth.

Drop teaspoons of blueberry sauce over the top of the cheesecake and gently swirl. Reserve remaining sauce for serving.

Bake at 275 degrees F for 1.5-2 hours, until the outer 2" are set and the center is still somewhat jiggly.

Turn oven off and let sit in warm oven for 1 more hour.

Remove from oven and set on the counter to cool to room temperature. Refrigerate at least 8 hours or overnight before slicing.

Remove from pan and serve with whipped cream (optional) and remaining blueberry sauce.