Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking pan.
In a bowl, whisk melted butter and granulated sugar until well combined.
Add eggs, pumpkin puree, and vanilla extract, mixing until smooth.
In another bowl, combine flour, baking powder, salt, and spices. Gradually add to the wet mixture, stirring just until combined.
Pour half the batter into the prepared pan, spreading it evenly.
Mix cocoa powder and chocolate chips into the remaining batter.
Drop spoonfuls of chocolate mixture onto the pumpkin batter.
Swirl the batters together with a knife or spatula.
Bake for 25-30 minutes or until a toothpick comes out clean.
Cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.
Cut into squares and enjoy!