In a medium bowl, fold the cream cheese until smooth to ensure it is soft.
Add brown sugar and stir until dissolved.
Mix in the egg and pumpkin.
Fold in the vanilla, cream, cinnamon, and allspice until smooth. Set aside.
For the brownies
Whisk together the melted butter and sugars in a large bowl.
Add the vanilla and eggs, whisking to incorporate.
Sift in the cocoa and flour to ensure there are no lumps. Add salt and baking powder. Fold until no dry streaks remain then fold in chocolate chips.
Prepare a 9x13 baking pan by spraying with nonstick baking spray. Line with one layer of parchment and spray parchment.
Pour half the brownie batter in the prepared pan and spread to an even layer. Pour cheesecake filling over brownie batter and spread evenly. Place remaining brownie batter on top of cheesecake layer, filling in clumps evenly.
Using a table knife, make figure-eight drawings all over the brownies, making sure the knife is touching the bottom of the pan. Do not worry about being too aggressive.
Bake in preheated oven until the center jiggles slightly and the edges are set, 45-60 minutes.
Remove from oven and cool completely, about 4 hours.
Using parchment sling, remove brownies from pan and cut into squares. Store in an airtight container in the refrigerator up to one week or in the freezer up to four weeks.