Preheat the oven to 325ºF, and spray a 9-inch springform pan with nonstick cooking spray.
Crush the Oreos in a food processor until finely-ground. Add the melted butter and mix until all the crumbs are moistened. Press firmly into the bottom of the pan. Bake in the oven for 8 minutes, then set aside to cool.
Make the Batter:
Place a large roasting pan in the oven on the bottom rack. Pour hot water into the pan, making sure it is about 1" deep. Close the oven door.
In the bowl of a stand mixer fitted with the paddle attachment, beat the cream cheese and sugar together until creamy. Scrape down the sides of the bowl, add the cornstarch, sour cream, lemon juice, zest, vanilla, and salt, and beat until incorporated. Beat in the eggs, two at a time, until combined--try not to overmix.
Pour batter into the crust, smoothing out the top. Bake cheesecake for 60-70 minutes, or until center appears nearly set when shaken. Turn off the oven and leave the oven door cracked. Allow cheesecake to rest in the oven for one hour.
After an hour has passed, remove the cheesecake from the oven. Place it onto a cooling rack to cool completely before covering it and chilling in the refrigerator for at least 8 hours.
Make the Topping:
In a medium saucepan, heat the blueberries over medium heat until they soften and their juices start to release, about 2-3 minutes.
In a separate bowl, combine the sugar, cornstarch, and salt. Add mixture to the blueberries and continue cooking until it begins to form a thick sauce, about 3-5 minutes.
Remove from heat and stir in the lemon juice. Pour into a shallow bowl and place in the refrigerator to cool completely.
To Assemble:
Pour the blueberry topping on top of the cheesecake and use an offset spatula or butterknife to spread evenly. Pipe a border of whipped cream along the edges of the cheesecake. Decorate with fresh lemon slices.
Cheesecake will stay fresh for up to 5 days if sealed tightly in a plastic container or covered with plastic wrap and stored in the refrigerator