In a large bowl, combine the flour, salt, ground black pepper, garlic powder, smoked paprika, onion powder, dried oregano, and cinnamon. Stir until the ingredients are well blended.
Add the chicken thighs to the bowl and use your hands to toss the chicken (you can wear disposable gloves), ensuring that it is thoroughly coated with the seasoned flour. Alternatively, you can place the flour and seasonings in a large Ziploc bag, add the chicken, and shake it until the chicken is well coated.
Preheat your air fryer to 365 degrees Fahrenheit (185 degrees Celsius).
Once the air fryer is ready, place the chicken thighs in the air fryer basket, skin-side up, in a single layer. Cook for 20 minutes.
After the chicken has cooked for 20 minutes, open the air fryer basket and spray or brush any remaining white flour areas of the chicken with cooking oil. Close the basket and continue cooking for another 5 minutes.
After 5 minutes, flip the chicken and cook for an additional 2 minutes, or until the internal temperature reaches 165 degrees Fahrenheit (74 degrees Celsius).
Remove the chicken from the air fryer and allow it to cool slightly. Serve with your favorite side dishes and enjoy!