Instructions

• Adjust the oven rack to the lower-middle position. Preheat oven to 350°F (180°C) (160°C for a fan oven). Line an 8×8-inch (20×20 cm) baking dish with parchment paper, leaving the paper to hang over two opposite sides for easy removal.
• Place the gingersnap cookies in a food processor and pulse until they become fine crumbs. If you don’t have a food processor, place the cookies in a sturdy zip-top bag and crush them with a rolling pin until finely ground.
• Add the melted unsalted butter and 1/4 cup packed light brown sugar to the crumbs and pulse or stir until evenly combined.
• Pour the crumb mixture into the prepared pan and press it firmly and evenly into the bottom of the pan (use the bottom of a measuring cup or the back of a spoon). Bake the crust for 7 minutes. Remove from the oven and transfer to a wire rack to cool while you prepare the fillings.
• Reduce the oven temperature to 325°F (165°C).
• In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), beat the softened cream cheese on high speed until completely smooth and fluffy, about 4–5 minutes.
• Add the granulated sugar and 1 tablespoon all-purpose flour to the creamed cream cheese. Mix on medium speed until fully incorporated and smooth.
• Add the full-fat sour cream, 1 large egg, 1 egg yolk, and 1 teaspoon vanilla extract. Mix on medium-low speed just until combined; scrape down the sides and bottom of the bowl and mix briefly again so the mixture is homogeneous. Spoon out a small amount of this cheesecake mixture and set it aside for topping.
• In a separate bowl, whisk together the pumpkin puree, 1/2 cup packed light brown sugar, 1/2 cup heavy whipping cream, 1 large egg, and 1 teaspoon vanilla extract until smooth and uniform.
• Add the 2 tablespoons all-purpose flour and 2 teaspoons pumpkin pie spice to the pumpkin mixture and stir until there are no dry streaks.
• Pour the remaining cheesecake mixture evenly over the cooled gingersnap crust and smooth the top with a spatula or the back of a spoon.
• Gently pour the pumpkin mixture over the cheesecake layer and smooth it lightly so it’s even.
• Drop small spoonfuls of the reserved cheesecake mixture over the pumpkin layer. Using a toothpick or the tip of a sharp knife, drag through the layers to create swirls—do this gently and don’t over-swirl.
• Bake the bars at 325°F (165°C) for 50–55 minutes, until the edges are set and the center still has a slight jiggle.
• Turn off the oven, crack the oven door open, and let the pan sit in the oven for about 20 minutes to cool slowly.
• Remove the pan from the oven and let it cool to room temperature on a wire rack. Then refrigerate the bars until firm, at least 4 hours or preferably overnight.
• Use the parchment overhang to lift the cheesecake from the pan. Trim edges if desired and cut into 16 squares. Serve chilled.