Preheat the oven to 325°F.

In a medium bowl, combine the 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 with an electric mixer until smooth and creamy. Gradually add 1 cup of sugar and continue to beat until well combined.

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

Stir in the sour cream until smooth. Pour half of the cheesecake batter over the cooled crust.

Drizzle half of the chocolate syrup over the batter, then sprinkle half of the chopped pecans on top. Pour the remaining cheesecake batter over this layer.

Repeat the process by drizzling the remaining chocolate syrup and sprinkling the remaining pecans on top of the final layer of batter.

Bake the cheesecake in the preheated oven for 55-60 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 1 hour.

Remove the cheesecake from the oven and let it cool to room temperature. Once cooled, refrigerate for at least 4 hours or overnight before serving.

Before serving, top with whipped cream and additional chocolate syrup if desired.