In a mixing bowl, combine graham cracker crumbs with melted butter until resembling wet sand. Press into the bottom of a chilled 9-inch springform pan.

In a large mixing bowl, beat cream cheese until smooth. Gradually add sugar and cornstarch, mixing until combined. Add eggs one at a time on low speed. Blend in sour cream, lemon juice, and vanilla extract.

Pour cheesecake filling over the prepared crust. Wrap in aluminum foil and place inside a larger roasting pan filled with hot water halfway up the sides. Bake at 302°F (150°C) for 30-45 minutes until edges are set.

Turn off the oven and crack the door open. Allow cheesecake to cool for one hour. Refrigerate overnight.

Carefully release the pan and slice. Serve with fresh berries or sauce if desired.