Preheat the air fryer to 400 degrees and prepare with a parchment paper insert for easy cleanup.
Add potatoes to a saucepan and cover with water, then add salt. Bring to a rolling boil over medium-high heat, then reduce heat and boil for 18 minutes, or until potatoes can be easily pierced with a fork or knife. Drain, then set potatoes on a flat surface.
Using a large glass, press down on the potato until skin breaks and it begins to flatten.
Add oil, seasonings, and garlic to a mixing bowl and whisk until combined.
Using a basting brush, cover each smashed potato generously with oil mixture on both sides, then place in air fryer basket.
Cook in the air fryer for 8 minutes.
Serve with melted butter and enjoy!