1. Preheat oven to 350°F (175°C) and line an 8×8 or 9×9 inch pan with parchment paper and spray lightly.

2. In a bowl, stir brownie mix, eggs, oil, water, and 1/3 cup pumpkin puree until just combined and pour two thirds into the pan.

3. Beat cream cheese and sugar until smooth, then add egg yolk, 1/2 cup pumpkin puree, pumpkin pie spice, and vanilla until blended.

4. Drop spoonfuls of cheesecake mixture over the brownie layer, then dollop remaining brownie batter on top.

5. Use a toothpick or knife to drag through both batters in figure-eight motions 4–6 times to create a swirl.

6. Bake for 40–45 minutes until edges are set and a toothpick shows moist crumbs; cool in pan for at least 1 hour.

7. Optionally chill 30 minutes before slicing and garnish with chips, nuts, or sea salt before serving.