Preheat your oven to 350°F, or the temperature indicated on your brownie mix or homemade recipe. Lightly spray a 9-inch square baking pan with cooking spray. Line it with parchment paper, leaving an overhang on two sides for easy removal after baking. Alternatively, you may use foil and then lightly spray it as well. Set the prepared pan aside.

Prepare the brownie batter according to the directions on the box, using any additional ingredients the box requires (typically eggs, oil, and water, not listed here). Once the batter is mixed, stir in the semisweet chocolate chips until evenly distributed. Set the brownie batter aside while you make the cheesecake layer.

In a stand mixer or with a hand-held mixer, beat the softened cream cheese until it is light and fluffy. Add the white sugar and continue beating until well combined. Beat in the egg and vanilla extract, mixing until smooth. Add the pumpkin and pumpkin pie spice, and beat again until the mixture is completely smooth and homogeneous.

Spread half of the brownie batter (from Step 2) evenly into the bottom of your prepared pan. Smooth the top using a spatula. Spoon the pumpkin cheesecake mixture (from Step 3) over the brownie batter and carefully spread it into a thin and even layer. Then, dollop the remaining brownie batter on top. Use the tip of a knife to swirl the layers together to create a marbled effect. I like to gently swirl just a few times for a nice contrast between the brownie and cheesecake.

Bake the assembled brownies in the preheated oven for 40 to 45 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs attached. Keep a close eye after 40 minutes, as baking times may vary. Let the brownies cool completely in the pan. Use the parchment or foil overhang to lift them out before cutting into squares. I recommend letting them chill for a bit in the fridge for cleaner slices and even better texture.