Preheat the oven to 325°F (163°C).

In a mixing bowl, combine graham cracker crumbs, sugar, and melted butter.

Press the mixture into the bottom of a 9-inch springform pan.

Bake for 10 minutes, then remove from oven and let cool.

In a large mixing bowl, beat the softened cream cheese until smooth.

Add sugar and vanilla extract, and mix until well combined.

Add eggs one at a time, mixing well after each addition.

If using, mix in sour cream and heavy cream until smooth.

Pour the filling over the cooled crust in the springform pan.

Bake in the preheated oven for 50-60 minutes, or until the center is set but slightly jiggly.

Turn off the oven and let the cheesecake cool in the oven with the door ajar for 1 hour.

Remove from the oven and refrigerate for at least 4 hours, preferably overnight.

Run a knife around the edge of the springform pan before releasing the sides.

Slice and serve chilled, optionally topped with fruit or whipped cream.