In a small bowl, stir together the canned pumpkin, cinnamon, ginger, nutmeg, and 1/4 teaspoon salt. Set aside.

In a separate bowl, beat the mascarpone cheese and cream cheese with 1/4 teaspoon salt until smooth. Add the pumpkin mixture and mix until just combined.

Add sugar, flour, and vanilla to the cream cheese and pumpkin mixture. Mix until just combined. Add the egg yolks one at a time, beating until thoroughly incorporated. Set aside.

Preheat your oven to 325°F. Prepare a 9 x 9-inch baking dish by buttering and lining with parchment paper.

In a large bowl, whisk together flour, cocoa powder, baking powder, and salt.

In a separate bowl, stir together melted butter and sugar. Whisk in the eggs and vanilla until combined. Stir in chocolate chips, then gradually add the flour mixture to the egg mixture, mixing until just combined.

Reserve 1/2 cup of the brownie batter for topping later. Spread the remaining brownie batter evenly into the prepared pan.

Pour the pumpkin cheesecake mixture over the brownie layer. Create 3 to 4 lines with the reserved brownie batter on top of the cheesecake layer.

Using a toothpick or small knife, swirl the brownie batter lines into the cheesecake to create a marbled effect.

Bake for 45 minutes or until the top is set and a tester comes out mostly clean.

Allow to cool completely, then refrigerate to chill before serving.