Cut the chicken thighs into bite-sized pieces.
Place the chicken in a large bowl and add olive oil, paprika, garlic powder, salt, black pepper, onion powder, and cayenne pepper.
Toss well until all pieces are evenly coated.
Thread the chicken onto 4 skewers, keeping the pieces packed closely together while leaving space at both ends.
Preheat the air fryer to 200°C (400°F).
Place the skewers in the air fryer basket and cook for 10 minutes.
Meanwhile, prepare the garlic parmesan butter by combining softened butter, Parmesan cheese, garlic, parsley, salt, and pepper.
Stir until smooth and brushable. If needed, microwave in 5-second intervals until creamy.
After 10 minutes, flip the Air Fryer Garlic Parmesan Chicken Skewers and brush with one-third of the butter mixture.
Air fry for 2½ minutes.
Flip again, brush with another third of the butter, and cook for another 2½ minutes.
Continue cooking until lightly charred and the internal temperature reaches 74°C (165°F).
Remove from the air fryer and brush with the remaining garlic parmesan butter.
Garnish with extra Parmesan cheese and fresh parsley if desired.
Serve immediately.