Preheat the air fryer to 400°F (200°C) for 5 minutes.
In a shallow bowl, place the all-purpose flour.
In a second shallow bowl, beat the eggs until combined.
In a third shallow bowl, combine the panko breadcrumbs, grated Parmesan cheese, garlic powder, dried Italian seasoning, salt, and black pepper.
Pat the chicken thighs dry with paper towels.
Dredge each chicken thigh in the flour, shaking off excess.
Dip the floured chicken thighs into the beaten eggs, coating completely.
Press the chicken thighs into the breadcrumb mixture, ensuring an even coating on all sides.
Lightly spray both sides of the breaded chicken thighs with olive oil spray.
Place the chicken thighs skin-side down in the air fryer basket in a single layer without overlapping.
Cook at 400°F (200°C) for 10 minutes.
Flip the chicken thighs and cook for an additional 5 minutes.
Spoon 1/4 cup marinara sauce over each chicken thigh.
Sprinkle 1/4 cup shredded mozzarella cheese evenly over the sauce on each thigh.
Return the chicken thighs to the air fryer and cook for 5 more minutes, or until the cheese is melted and bubbly and the chicken reaches an internal temperature of 165°F (74°C).
Carefully remove the chicken thighs from the air fryer and let rest for 3 minutes before serving.