Preheat & Prep: Preheat oven to 325°F (165°C). Line the bottom of a 9-inch springform pan with parchment paper and lightly grease the sides.

Make the Crust: In a medium bowl, combine graham cracker crumbs, sugar, and melted butter. Stir until mixture resembles wet sand. Press evenly into the bottom of the springform pan. Bake for 8–10 minutes until fragrant and lightly golden. Let cool while preparing filling.

Prepare Cheesecake Batter: In a large mixing bowl, beat softened cream cheese and sugar until smooth and creamy (about 2 minutes). Add eggs one at a time, mixing just until combined after each. Stir in vanilla and sour cream until smooth. Do not overmix to avoid cracks later.

Make the Pumpkin Swirl: In a separate bowl, combine pumpkin puree, sugar, pumpkin pie spice, and flour. Add 1 cup of the cheesecake batter to the pumpkin mixture and stir until smooth.

Assemble Layers: Pour the plain cheesecake batter into the cooled crust. Drop spoonfuls of the pumpkin mixture on top. Using a knife or skewer, gently swirl the pumpkin mixture into the cheesecake batter to create a marbled design (avoid over-swirling for best effect).

Bake: Place the pan on a baking sheet. Bake for 55–65 minutes, or until edges are set and the center is slightly jiggly. (Tip: Avoid opening the oven door during baking to prevent cracks.)

Cool Gradually: Turn off the oven and crack the oven door. Let cheesecake sit inside for 1 hour to cool slowly. Then remove, cover loosely, and refrigerate for at least 4 hours, preferably overnight.

Serve: Carefully remove from springform pan and transfer to a serving plate. Slice with a sharp knife (wipe clean between cuts for neat slices). Garnish with whipped cream, caramel drizzle, or nuts if desired.