Preheat oven to 350F. Line a 9x13-inch pan with parchment paper or foil, and spray with nonstick spray.

Make the crust: Pulse cinnamon graham crackers in a food processor until fine crumbs. Mix with melted butter until combined. Press mixture into the prepared pan to form an even crust layer.

Prepare the filling: In a large bowl, beat softened cream cheese with sugar until smooth. Mix in sour cream and vanilla. Add eggs one at a time, beating just until incorporated. Fold in pumpkin puree, pumpkin pie spice, cinnamon, flour, and salt.

Pour the filling over the crust in the pan. Swirl with a toothpick or knife to create a marbled effect.

Bake for 40 minutes, or until set on top. Rotate the pan halfway through baking.

Allow to cool in the pan for 1 hour, then chill in the fridge for at least 2 hours or overnight.

Slice and serve chilled, optionally topped with whipped cream or caramel sauce.