Preheat the air fryer to 400°F (200°C) for about 5 minutes.
In a large bowl, combine the cleaned mushrooms, olive oil, ranch seasoning, garlic powder, onion powder, salt, and pepper. Toss until the mushrooms are evenly coated.
Place the seasoned mushrooms in a single layer in the air fryer basket. You may need to do this in batches depending on the size of your air fryer.
Cook the mushrooms in the air fryer for 10-12 minutes, shaking the basket halfway through to ensure even cooking. The mushrooms should be golden brown and crispy.
Once cooked, remove the mushrooms from the air fryer and garnish with fresh parsley before serving.