Preheat your oven to 300 degrees Fahrenheit (150 degrees Celsius).
Grease a 9-inch springform pan.
Mix graham cracker crumbs and melted butter in a medium bowl.
Press this mixture evenly into the bottom of the prepared pan.
Chill the crust in the refrigerator while preparing the filling.
Using an electric mixer, beat the softened cream cheese in a large bowl until smooth and fluffy.
Add sugar, cornstarch, and salt, beating on low speed until each ingredient is incorporated.
Add sour cream, heavy cream, vanilla extract, and lemon juice.
Beat until the mixture is completely smooth and lump-free.
Pour the filling over the chilled crust.
Place a small pan half-filled with hot water on the lower rack of your oven to create a humid environment and prevent cracking.
Bake the cheesecake in the preheated oven for 55-70 minutes.
Allow the cheesecake to cool in the oven with the door slightly open for about an hour.
Then, refrigerate it for at least 4 hours or overnight before serving.