Preheat the oven to 400 degrees F (200 degrees C).

Set up a breading station with 4 shallow dishes. Add milk to the first dish. Mix flour and seasoning blend together in the second dish. Add ranch dressing to the third dish. Mix panko bread crumbs and dry ranch dressing in the fourth dish.

Dip each mushroom first into milk, then flour, shaking off excess flour. Dip in ranch dressing, followed by panko bread crumbs. Set mushrooms in a shallow air fryer pan or the air fryer basket and spray with nonstick cooking spray.

Air-fry until mushrooms are golden, about 7 minutes.