Preheat oven to 350°.
Line a 9x13 baking pan with parchment paper for easier removal or spray pan with nonstick cooking spray.
In a large microwave safe bowl combine the bugtter and semi-sweet chocolate chips. Heat for 30 seconds then remove and stir. Heat another 30 seconds, remove and stir. Microwave another 30 seconds if needed.
Add each ingredient one at a time, stirring until combined, in this order:
Cocoa powder, sugar, vanilla and eggs. Beat until smooth.
Stir in the baking powder and salt.
Add the flour and stir until mixed.
In a separate bowl, blend cream cheese and sugar until smooth.
Add egg, cinnamon and nutmeg and mix until well combined.
Spread 1/2 of the brownie batter in pan. Pour pumpkin mixture over the top and spread.
Place big dollops of remaining batter over mixture.
Take knife and swirl through the brownie and pumpkin to create a marbled pattern.
Bake at 350° for 50 minutes or until a toothpick comes out with a few crumbs.