Place 1 cup of the Italian bread crumbs in a large bowl. In another large bowl, combine the remaining Italian crumbs, the Panko bread crumbs, salt, and pepper, then whisk together.
Dip the string cheese one at a time. First in the egg wash, then in the Italian breadcrumbs, then egg wash again, then the large bowl with the Panko bread crumbs.
Line air fryer basket with air fryer parchment paper. Place 6 string cheese sticks at a time in the air fryer. The parchment paper prevents the cheese from melting down and through the air fryer grate. Spray the mozzarella sticks with olive oil.
Bake on air fryer mode at 350F for 2 minutes. Flip the sticks over, spray with olive oil, and air fryer 3 more minutes.
Serve with marinara sauce.
If you would like to make these air fryer mozzarella sticks ahead of time, you certainly can. Prepare the sticks and place them on a waxed paper-lined baking sheet. Freeze for a couple hours, then move the frozen mozzarella sticks to a freezer bag. They can be stored in the freezer for 2 months.
These mozzarella sticks are best enjoyed immediately, but you can reheat them in the air fryer at the same temperature for half the time specified in the recipe.