Start by gently crushing the panko breadcrumbs using a rolling pin or cooking mallet.
Mix together the breadcrumbs, grated parmesan, Italian seasoning, salt, and garlic powder in a large, shallow bowl.
Pour the all-purpose flour into another shallow bowl.
In one more shallow bowl, whisk together two eggs.
Dip an unwrapped string cheese stick into the flour, then the egg wash, then the breadcrumb mixture.
Repeat the dipping process so the cheese stick is double coated.
Continue breading until all of the cheese sticks are covered. Add them to a large tray covered with parchment paper.
Freeze the cheese sticks for at least one hour; do not skip this step! Freezing helps to avoid the mozzarella sticks from exploding in the air fryer. Spray avocado oil (or any oil-based cooking spray) on the frozen cheese sticks. Add them to your air fryer tray lined with parchment paper. Be sure to avoid overcrowding your air fryer basket. I recommend cooking in batches. Air fry at 390°F for 5 minutes.
Flip the sticks, spray a bit more cooking spray on the other side, then cook for an additional 2-3 minutes.
Serve hot with freshly chopped parsley and a saucer of marinara sauce. Enjoy!