In a medium bowl, combine the canned pumpkin, cinnamon, ginger, nutmeg, and ¼ teaspoon of salt, stirring until smooth. In a separate bowl, mix the mascarpone and cream cheese until fluffy, then stir in the sugar, egg yolks, and vanilla extract. Fold the pumpkin mixture into the cheese mixture gently until fully incorporated; set aside as you prepare the brownie batter.

Preheat your oven to 325°F (163°C) and prepare a 9x9-inch baking dish by greasing it lightly with butter or lining it with parchment paper for easy removal.

In a large mixing bowl, whisk together the flour, cocoa powder, baking powder, and remaining salt. In a separate bowl, combine the melted butter, sugar, and eggs, mixing until well-blended. Gradually stir the dry ingredients into the wet ingredients until just combined, then fold in the chocolate chips.

Spread half of the brownie batter in an even layer in the prepared baking dish. Next, spoon the cheesecake mixture over the brownie layer and smooth it out. Dollop the remaining brownie batter on top and swirl it into the cheesecake mixture with a knife.

Place the baking dish in the preheated oven and bake for 45 minutes, or until the top is set and a toothpick inserted comes out mostly clean.

Allow the brownies to cool in the pan for about 30 minutes, then transfer them to the refrigerator and chill for at least 2 hours before slicing.