Preheat oven to 350°. In a small saucepan combine the Lemon Blueberry Swirl ingredients, bring to a boil and simmer for 10 minutes. Strain and set aside to cool.
Spray a 10" springform pan with oil and cover the bottom and outer edges with heavy tin foil in preparation for a water bath. Make sure water will not be able to get inside the tin foil. Mix the crust ingredients and press into the bottom of the pan. Bake 8 minutes then set aside.
Using a stand mixer and paddle attachment, or a medium bowl and hand blender, whip the cream cheese until all the lumps are gone. Add the sugar and whip again then scrape down the bowl. Mix in the sour cream. Next add the eggs one at a time, scraping down after each addition. Add the vanilla, lemon juice, sift in cornstarch and salt. Mix until just combined then pour into the crust.
Spoon the lemon blueberry mix onto the batter in a few different places over the cheesecake. Take a knife and swirl it through the blueberry mixture a few times to create your beautiful Lemon Blueberry Swirl. Check out the photos posted above this recipe!
Set the cheesecake into a roasting pan and add boiling water to the pan until it comes halfway up the tin foil. Check out my Cheesecake Tips for more details on how to use a water bath and so much more! Bake for 50-60 minutes. The outer edge will be puffy but the middle will still look a bit jiggly.
Turn off the oven and prop the door ajar with a wooden spoon. Allow the cheesecake to rest for 1 hour before pulling it out. Leave it on the counter until it comes to room temperate before refrigerating. Refrigerate for at least 6 hours, preferably overnight.
Whip the cream until soft peaks form. Sift in icing sugar, add the vanilla, lemon juice and zest. Whip until hard peaks form. Pipe onto cooled cheesecake. Sprinkle with additional lemon zest if desired.