• Preheat your oven to 350°F (175°C).
• In a medium bowl, combine melted butter, ¼ cup sugar, and graham cracker crumbs. Press the mixture into the bottom and halfway up the sides of a 10-inch springform pan.
• In a stand mixer bowl, beat cream cheese until smooth. Add 1 ½ cups sugar and beat until combined.
• Scrape down the bowl's sides and add eggs one at a time, beating after each addition.
• Mix in vanilla, lemon juice, cornstarch, and sour cream until smooth.
• Pour the filling into the graham cracker crust in the springform pan.
• Bake for about 1 hour until the edges are set, and the center is slightly jiggly. Let it cool in the oven with the door cracked open.
• Once cooled, refrigerate the cheesecake for at least 4 hours or overnight.

Blueberry Topping:

• In a 2-quart saucepan, combine frozen blueberries, ¼ cup water, lemon juice, and 1 cup sugar.
• Heat over medium-high heat until it boils. In a separate bowl, mix cornstarch and ½ cup water to create a slurry.
• Stir the cornstarch slurry into the blueberry mixture until it thickens to a gel-like consistency.
• Let the blueberry topping cool to room temperature.
• Pour the cooled blueberry topping over the chilled cheesecake.
• Refrigerate for at least 2 hours or preferably overnight before serving.