Preheat the air fryer: Set to 375°F (190°C) for 2–3 minutes.
A preheated basket helps the bread crisp evenly.
Assemble the sandwich: Lay out two slices of bread. Spread a thin layer of butter or mayo on one side of each slice (this will be the outside). Flip the slices so the unspread sides face up.
Add fillings: Place cheese on one slice, then a generous layer of ham, then more cheese.
The cheese-on-both-sides trick helps “glue” the sandwich together. Add optional mustard or seasonings on the ham if you like.
Close and press: Top with the second slice, buttered side facing out. Press gently to compact the sandwich slightly for even melting.
Prep the basket: Lightly spray the basket or use a small square of parchment with holes.
Avoid solid parchment unless the basket is weighted by the sandwich.
Air fry the first side: Place the sandwich in the basket. Cook at 375°F (190°C) for 4–5 minutes.
Flip and finish: Carefully flip with tongs. Air fry another 2–4 minutes, until the bread is golden and the cheese is fully melted.
Check doneness: Peek between the slices; if the cheese isn’t melted, cook 1–2 minutes more.
If the bread is browning too fast, lower the temp to 360°F (182°C).
Rest and slice: Let the sandwich rest for 1 minute to set the cheese, then slice diagonally. Serve hot.