Heat the oven to 350°F (175°C). Line a 9 x 13-inch baking pan with parchment paper, leaving some overhang for lifting, or lightly grease the pan.

Combine the graham cracker crumbs, 1/4 cup granulated sugar, and melted unsalted butter. Press the mixture firmly and evenly into the bottom of the prepared pan, then bake for 8–10 minutes and cool briefly.

Beat the softened cream cheese and 1 cup granulated sugar until smooth. Add the eggs one at a time, mixing just until each is incorporated, then stir in the vanilla extract.

Reserve about 1 to 1 1/2 cups of the plain cheesecake batter. Mix the pumpkin purée, cinnamon, ginger, and nutmeg into the remaining batter.

Spread the pumpkin batter over the cooled crust. Spoon or dollop the reserved plain cheesecake batter over the pumpkin layer.

Run a thin knife through the batter in several gentle figure-eight motions to create the swirl. Bake for approximately 35–45 minutes, until the edges are set and the center has only a slight jiggle.

Cool the cheesecake completely, then refrigerate for at least 2 hours, preferably overnight. Lift it from the pan, cut into bars with a sharp warmed knife, and wipe the blade clean between cuts.