Preheat oven to 350℉ and line an 8x8 pan with parchment paper.
In a bowl, melt together the butter and chocolate chips until smooth. Mix in the eggs, vanilla, and brown sugar until smooth.
Mix in the dry ingredients for the brownie batter. Set this batter aside while you make the pumpkin swirl.
In a bowl, mix together the pumpkin swirl ingredients until smooth.
Spread about ¾ of the brownie batter into the prepared pan. Add dollops of the pumpkin swirl evenly over top of the batter before spreading the rest of the brownie batter on top. Use a knife to swirl the pumpkin into the brownie batter.
Bake for about 30 minutes and let cool before slicing and enjoying!