Preheat your oven to 325°F (165°C). Line a 9x9 inch metal baking pan with parchment paper, leaving a 2-inch overhang on the sides.

In a medium bowl, stir together the graham cracker crumbs, brown sugar, cinnamon, and melted butter until it resembles wet sand. Press firmly into an even layer across the bottom of the pan.

Bake the crust for 9-10 minutes until fragrant. Remove from the oven and set aside to cool slightly.

In a large mixing bowl using a hand mixer on medium-low speed, beat the softened cream cheese and granulated sugar for 2 minutes until completely smooth and lump-free.

Beat in the sour cream and vanilla extract. Add the room-temperature eggs one at a time on low speed, mixing just until incorporated.

Scoop 1 1/4 cups of the plain vanilla cheesecake batter into a separate bowl and whisk in the pumpkin puree, pumpkin pie spice, and 1 tablespoon of flour until smooth.

Alternate spoonfuls of the vanilla cheesecake batter and spiced pumpkin batter over the crust. Use a butter knife or offset spatula to gently swirl the two batters into a figure-eight marble pattern.

Bake at 325°F for 35-38 minutes until the edges are set and the center has a slight wobble. Cool at room temperature for 1 hour, then refrigerate for at least 3 hours before slicing into 16 squares.