Preheat the oven to 350°F. Line an 8-inch square baking pan with parchment paper or foil, leaving an overhang on all sides. Spray with nonstick cooking spray.

In a food processor, pulse the crackers until finely ground. Add the butter and pulse until moistened. Press the crumb mixture into the bottom of the prepared pan using the bottom of a measuring cup, shot glass, or tart tamper. Bake until fragrant, about 10 minutes. Place on a cooling rack to cool completely. Maintain oven temperature.

In a large bowl, use an electric mixer to beat the cream cheese, sugar, and pumpkin at medium-high speed until completely smooth. Add the eggs, one at a time, and beat until combined. Add the flour, spices, and salt and beat until combined. Be careful not to overbeat.

Place the chopped chocolate in a microwave-safe bowl; microwave in 30-second bursts, stirring between each, until melted and smooth. Add 1 cup cheesecake batter and stir to combine.

Pour the pumpkin cheesecake batter into the prepared pan.

Drop dollops of the chocolate batter mixture on top of the pumpkin layer, and swirl with a butter knife. Bake at 350°F until the edges are slightly golden and the cheesecake is set but still slightly jiggly in the center, about 40 minutes. Do not overbake.

Place the cheesecake on a cooling rack to cool completely in its pan. Cover and chill in the fridge until firm, at least 4 hours and up to 2 days. Using the parchment overhang, transfer cheesecake to a cutting board to cut into squares before serving.