Review all recipe notes and instructions before beginning.
Place the potatoes and salt in a large pot. Add enough water to completely cover the potatoes. Bring the pot to a boil over medium high (or high) heat. Boil for 11-13 minutes or until a fork can easily pierce the potato. Do not overcook. Drain the water.
In a large bowl, gently toss the potatoes and olive oil.
On a large baking sheet or cutting board, one by one, gently smash the potatoes with the bottom of a flat glass.
Transfer the smashed potatoes to the air fryer basket in a single layer. (Cook in batches if needed.)
Air fry at 400 degrees for 15 minutes, flipping halfway through.
While the potatoes are air frying, combine the butter, parmesan, garlic, italian seasoning, and salt in a small bowl. Once the potatoes are done, brush the butter mixture on each potato while they are still hot.