Preheat the Oven: Preheat your oven to 325°F (163°C).
Prepare the Crust:
In a medium bowl, mix the graham cracker crumbs, sugar, and melted butter until well combined.
Press the mixture firmly into the bottom of a 9-inch springform pan. Bake for 10 minutes, then remove and let cool while you prepare the filling.
Make the Filling:
In a large mixing bowl, beat the softened cream cheese with an electric mixer on medium speed until smooth and creamy (about 2-3 minutes).
Gradually add the sugar and vanilla extract, mixing until combined.
Add the eggs one at a time, mixing on low speed after each addition just until incorporated. Be careful not to overmix.
If using, fold in the sour cream and flour until just combined.
Bake the Cheesecake:
Pour the filling into the cooled crust, spreading it evenly.
Bake in the preheated oven for about 1 hour, or until the center is set but slightly jiggly.
Cool and Refrigerate:
Once baked, turn off the oven and crack the door open. Let the cheesecake cool in the oven for about 1 hour to prevent cracking.
After cooling, refrigerate for at least 4 hours or overnight for best results.
Serve:
Before serving, you can top the cheesecake with fresh fruit, chocolate sauce, or whipped cream, if desired.