Preheat the air fryer to 370°F (188°C) for 3–5 minutes. A hot basket helps the crackers stay crisp and the marshmallows toast evenly.

Prep the base. Line the air fryer basket with a piece of foil or a liner. Lightly spritz with nonstick spray if you like. Arrange graham cracker halves in a single layer so they’re flat and not overlapping.

Add chocolate. Place chocolate squares on top of each graham half. Don’t overdo it—two small squares per cracker usually melt and spread nicely.

Top with marshmallows. Use one large marshmallow per cracker, placed upright, or a small handful of minis. Press gently so they make contact with the chocolate but don’t squish flat.

Air fry for 3–4 minutes, checking at the 3-minute mark. You’re looking for lightly toasted tops and softened chocolate. If you like them darker, add 30–60 seconds, but watch closely—marshmallows can go from golden to burnt fast.

Finish and assemble. Carefully lift the crackers out (they’ll be hot). Optionally, sprinkle a pinch of flaky salt over the marshmallows to balance the sweetness. Top with another graham cracker half and press lightly to make a sandwich, or serve open-faced with a fork if you prefer less mess.

Serve right away. S’mores are best warm while the marshmallow is stretchy and the chocolate is melty.