01 - Preheat the oven to 175°C (350°F) and line a 20x20 cm (8x8 inch) baking pan with parchment paper.
02 - In a large bowl, whisk together melted butter and granulated sugar until smooth. Add eggs, vanilla extract, and salt, mixing thoroughly. Sift in cocoa powder and flour, stirring until just combined.
03 - In a separate bowl, blend pumpkin puree, egg, granulated sugar, flour, cinnamon, nutmeg, and ginger until smooth.
04 - Pour brownie batter into the prepared pan, reserving a few spoonfuls. Evenly distribute the pumpkin swirl mixture over the brownie base. Drop remaining brownie batter in dollops across the top.
05 - Using a skewer or knife, gently create marbled patterns by swirling the pumpkin and brownie mixtures together without over-mixing.
06 - Transfer pan to the oven and bake for 30–35 minutes or until a toothpick inserted into the center comes out mostly clean with slight crumbs.
07 - Allow brownies to cool in the pan for at least 20 minutes before lifting out and slicing into equal portions.