Preheat your oven to 350°F.

In a bowl, add the brownie mix along with the ingredients listed on the box. Whisk until a thick, brown batter forms. Set aside.

Stir the melted butter and pumpkin puree in another bowl until well combined.

Add the brown sugar, white sugar, eggs, and vanilla extract to the pumpkin mixture. Whisk until smooth.

Fold in the remaining ingredients (dry): all-purpose flour and pumpkin pie spice. Blend the dry ingredients into the wet, gently mixing until a thick batter forms.

In a cast iron skillet, alternate spoonfuls of the pumpkin batter and brownie batter until you've used all the mixture, ensuring both are evenly spread.

Using a butter knife, swirl through the batters to create a marbled effect.

Bake for 35-40 minutes, or until the top looks shiny and the center is fully cooked.

Remove from the oven and let cool for a few minutes at room temperature.

Serve with ice cream and enjoy the flavor!