Cut chicken breasts in half to make four thin breasts. Place one thin breast between two pieces of plastic wrap and pound into a thin, even piece with a meat tenderizer. Repeat with the remaining chicken.
In a small bowl, stir together the mayo and minced garlic. Spread the garlic mayo all over the chicken breasts.
In a shallow bowl, combine the Panko bread crumbs, Parmesan cheese, salt, and pepper. Place a chicken breast into the bread crumbs and press down. Flip and coat the other side. Repeat with the remaining chicken.
Coat the air fryer basket with olive oil spray. (Do not use PAM, it can damage some baskets.)
Place the chicken in the basket and cook for 8 minutes. Flip and cook for another 5-7 minutes until golden brown and crispy. (Repeat as needed, you don't want to overcrowd the basket.)
Remove chicken and serve warm with extra Parmesan cheese and chopped parsley for garnish.