Preheat oven to 325°F (165°C). Line a 9x13-inch metal baking pan with parchment paper, leaving an overhang on the sides for easy lifting. In a bowl, combine graham cracker crumbs, sugar, melted butter, and cinnamon until mixture resembles wet sand. Press firmly and evenly into the bottom of the prepared pan. Bake for 8 minutes, then remove and cool slightly.

In a large mixing bowl with a hand or stand mixer fitted with the paddle attachment, beat the softened cream cheese and sugar on medium-low speed for 2 minutes until perfectly smooth and creamy. Beat in the eggs one at a time on low speed just until blended. Add vanilla extract. Do not overmix.

Transfer 1 cup of the plain cream cheese batter into a separate medium bowl. To the remaining batter in the large bowl, add the pumpkin puree, cinnamon, nutmeg, ginger, cloves, and salt. Whisk gently until fully incorporated and uniformly orange.

Pour the spiced pumpkin batter over the pre-baked graham cracker crust and smooth with an offset spatula. Dollop the reserved white cream cheese batter over the top in spoonfuls. Use a butter knife or wooden skewer to gently drag through the dollops in gentle figure-eight motions to create an elegant marbled swirl. Bake at 325°F (165°C) for 32 to 36 minutes until edges are set and center has a slight jiggle.

Turn off oven, prop the door open slightly, and let the cheesecake rest inside for 20 minutes to prevent cracking. Remove and cool completely to room temperature on a wire rack, then refrigerate for at least 4 hours (preferably overnight). Lift bars out using parchment overhang and slice into 16 neat squares using a sharp knife wiped clean between cuts. Top with spiced whipped cream before serving.