In a mixing bowl, combine the graham cracker crumbs with melted unsalted butter until the mixture resembles wet sand. Firmly press this mixture into the bottom of a 9-inch springform pan and refrigerate for 30 minutes.

Beat softened cream cheese with granulated sugar and cornstarch until smooth and fluffy. Gradually add large eggs one at a time, then mix in sour cream, vanilla extract, and lemon juice until creamy.

Pour the filling over the chilled crust, spreading it evenly. Wrap the bottom of the springform pan in aluminum foil, place it in a larger roasting pan, and add hot water until halfway up the sides. Bake at 302°F (150°C) for 30-45 minutes.

Turn off the oven and crack open the door. Let the cheesecake cool for about an hour. Then, refrigerate overnight to set completely.