Preheat air fryer to 200 Celsius and place the marshmallow inside.
Bake for 3 minutes. Once done, the marshmallow will have expanded.
Place a chocolate bar on top of the marshmallow.
Bake at 140 Celsius for 1-2 minutes until the chocolate has slightly melted.
Get a cookie from the supermarket (recommended to be Hafsang or Mary's).
Melted chocolate with marshmallow will stick together easily. Enjoy with crushed cookies.
For an extra treat, make a mini s'more sandwich by placing it between two crushed cookies.