Note, I made this and then divided it into 2 pans for my air fryer.
Start by preparing your brownies per the box instructions, when you are down, mix everything together.
Line your brownie with aluminum foil, or parchment paper, or leave it as is. Then use a non-stick cooking spray, spray the bottom of your pan (or foil/parchment paper)
Pour your brownie mix into the prepared pan.
Set the pan in your air fryer, for 350 degrees F. for 15 minutes
After 15 minutes, check the brownies, and then adjust the time for that. I always put mine in at 5-minute intervals and check them until they are done.
Note: The exact time for your brownies, depends on your machine, wattage, how thick the brownies are, etc.
Let cool, after you take them out of the air fryer.
Plate, serve & enjoy!