Preheat your oven to 325°F (163°C) and grease a 9 x 9-inch baking dish, lining the bottom with parchment paper.

In a medium bowl, combine canned pumpkin, cinnamon, ginger, nutmeg, and salt. Stir until well blended and set aside.

Beat together mascarpone cheese and cream cheese with a pinch of salt until smooth. Gradually add sugar, flour, vanilla extract, and egg yolks, mixing until smooth. Fold in the pumpkin mixture.

In another bowl, whisk together flour, cocoa powder, baking powder, and salt. Mix melted butter and sugar until combined, then whisk in eggs and vanilla. Incorporate dry ingredients until just mixed.

Spread half of the brownie batter in the prepared baking dish. Pour cheesecake layer over it evenly, then drop spoonfuls of remaining brownie batter on top and swirl with a toothpick.

Bake for approximately 45 minutes, until the top is set and a toothpick inserted comes out mostly clean. Let cool completely on a wire rack.

Refrigerate for at least an hour before slicing for cleaner cuts.