01 -  Preheat oven to 350°F. Line an 8x8-inch baking pan with parchment paper, ensuring an overhang for easy removal. 
 02 -  In a medium bowl, whisk together melted butter and granulated sugar until smooth. Beat in eggs and vanilla extract until fully incorporated. 
 03 -  Sift in cocoa powder, flour, salt, and baking powder. Stir gently with a spatula just until combined, being careful not to overmix. 
 04 -  Reserve 1/4 cup of brownie batter. Spread the remaining batter evenly over the base of the prepared pan. 
 05 -  In a separate bowl, beat softened cream cheese until smooth. Add pumpkin puree, granulated sugar, egg yolk, vanilla extract, cinnamon, nutmeg, ginger, and pinch of salt. Mix until creamy and well combined. 
 06 -  Dollop the pumpkin mixture over the brownie base in large spoonfuls. Distribute reserved brownie batter in small spoonfuls across the top. Using a knife or skewer, gently swirl the two batters to create a marbled pattern—avoid over-swirling. 
 07 -  Bake for 35 to 40 minutes, or until the center is just set and a toothpick inserted comes out with a few moist crumbs. 
 08 -  Let cool completely in the pan on a wire rack before removing and cutting into squares.