Preheat the air fryer to 370°F (188°C) for 3 minutes. A warm basket helps the marshmallows toast evenly.
Prep the base: Place 4 graham cracker squares on a small piece of parchment or directly in the basket.
Top each with one marshmallow. If your marshmallows are very tall, gently squish them a bit so they don’t roll.
Air fry for 2–3 minutes, watching closely at the 2-minute mark. You want a golden top and a soft center.
Every air fryer runs slightly differently, so keep an eye on color.
Add the chocolate: Carefully open the basket and place 1–2 chocolate rectangles on each toasted marshmallow. The heat will begin to soften them.
Top and warm: Add the remaining graham cracker squares on top to make sandwiches. Press lightly to secure.
Air fry for another 20–30 seconds, just to help the chocolate melt. Don’t overdo it or the crackers can scorch.
Rest briefly: Let the s’mores sit for 30–60 seconds. This allows the chocolate to finish softening and keeps everything from sliding out.
Customize (optional): Lift the top cracker and add a thin swipe of peanut butter, a slice of strawberry, or a pinch of flaky salt before serving.