Preheat the oven to 350ºF and adjust the rack to the middle position. Line an 8 x 8 – inch baking dish with parchment paper (like this). Pour the brownie batter into the baking dish and spread evenly with a spatula.
Whisk the pumpkin puree, cream, eggs, coconut sugar, pumpkin pie spice and vanilla until smooth. Spoon large dollops of the pumpkin mixture over the brownie batter. Using a knife, swirl the pumpkin puree mixture and brownie batter together. Bake for 30-35 minutes until a cake tester inserted in the middle of the pan comes out with a few moist crumbs (don’t overbake!). Cool and serve.
I found these are most delicious when served at room temperature.