Grease the Air Fryer Basket with cooking spray and then slide inside.
Adjust the temperature of Air Fryer to 350 °F to preheat for 5 minutes.
Remove the outer leaves from the cauliflower head.
In a small bowl, add mustard and mayonnaise and mix well.
Spread mustard mixture over cauliflower head and sprinkle with salt, black pepper and Parmesan cheese.
Spray the cauliflower head with cooking spray.
After preheating, arrange the cauliflower head into the greased Air Fryer Basket in a single layer.
Slide the basket into Air Fryer and set the time for 30 minutes.
While cooking, spray the cauliflower head with cooking spray after every 10 minutes.
After cooking time is finished, remove the cauliflower head from Air Fryer and place onto a platter.
Garnish with parsley and serve.