Start by brining the chicken legs in 20 ounces of water and 1 ounce of kosher salt.
To make the brine, first put the salt and half the water in a small saucepan. Heat until the salt has dissolved. Then, add the remaining water to help cool it down.
Put the chicken legs in a ziplock bag. Pour the cooled brine into the ziplock bag with the chicken, making sure it's completely submerged. Then refrigerate for at least 30 minutes or up to a day.
In a small bowl, add the garlic powder, onion powder, baking powder, paprika, salt, and black pepper. Mix until completely combined and set aside.
Preheat the Air Fryer to 400 degrees.
Remove the chicken from the brine and pat dry with a paper towel. Add the chicken to a medium bowl. Toss with a little olive oil and add the seasoning.
Place the chicken legs in the air fryer basket and cook for 10 minutes. Carefully flip the chicken and cook for another 8 minutes.
Baste one side of the chicken liberally with BBQ and cook for 3 minutes. Flip and baste the other side with BBQ sauce and cook for another 2-3minutes or until internal temperature reaches 165 degrees.
Allow the chicken to rest for 5 minutes before enjoying.