Preheat the oven to 325°F.

In a medium bowl, combine graham cracker crumbs, melted butter, and 2 tablespoons of sugar. Mix until well combined.

Press the mixture firmly into the bottom of a 9-inch springform pan to form the crust. Bake for 10 minutes, then remove from the oven and let cool.

In a large mixing bowl, beat the softened cream cheese and ½ cup of sugar until smooth and creamy.

Add the vanilla extract and mix well.

Add the eggs one at a time, mixing on low speed until just combined after each addition. Be careful not to overmix.

Fold in the sour cream and chopped pistachios, and if using, the pistachio extract.

Pour the cheesecake batter over the cooled crust in the springform pan, smoothing the top with a spatula.

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

Turn off the oven and crack the door open, allowing the cheesecake to cool in the oven for about 1 hour.

After cooling, refrigerate the cheesecake for at least 4 hours, preferably overnight, to set completely.

Before serving, top with whipped cream and additional chopped pistachios if desired.