Preheat your oven to 325°F (160°C). Prepare a 9-inch springform pan by greasing it lightly.

In a medium bowl, combine graham cracker crumbs, sugar, and melted butter. Mix until the crumbs are well coated. Press the mixture firmly into the bottom of the springform pan. Bake for 10 minutes, then set aside to cool slightly.

In a large mixing bowl, beat the softened cream cheese until creamy. Gradually add in sugar, mixing well. Incorporate the vanilla, eggs, and sour cream one at a time, making sure everything is well blended and smooth.

In another bowl, mix together pumpkin puree, sugar, pumpkin pie spice, and eggs until well combined.

Pour half of the cheesecake filling over the cooled crust. Spoon half of the pumpkin mixture over the cheesecake, then use a knife to create swirls. Repeat with the remaining fillings.

Bake in the preheated oven for 50-60 minutes, or until the edges are set but the center still has a slight jiggle. Turn off the oven and leave the cheesecake inside for an additional hour.

Remove the cheesecake from the oven and let it cool to room temperature. Once cooled, refrigerate for at least 4 hours, ideally overnight, to allow the flavors to meld.