My son thought it was too crunchy (sigh), but the air fryer lets you adjust time and temperature to get the right texture. Air fryers vary in strength, thus you may need to adjust my instructions.
The outside of grilled cheese in a skillet can develop to the color you want or burn before melting. This can be avoided by griddling the bread's interior or covering the pan.
Air fryers are best for melt due to their extreme heat. Air fryer grilled cheese can be sliced after a minute or two to solidify and cool. Also easy to slice cheese with the gadget.
I got great results with vegan cheese in the air fryer, almost like dairy. Even after precooking the bread, the shreds of a vegan grilled cheese in the skillet did not melt the same way.
As I've mentioned, the air fryer is a low-fat cooking method. Color, flavor, and heat protection are still needed. A light fat covering on the bread's outside is enough.
Mayo is my favorite, but oil or softened/melted butter (salted or unsalted) work too. In the air fryer, you need much less fat than in a skillet, especially if you add additional after flipping the sandwich.
Making two sandwiches in one skillet is difficult, especially if you toast the bread. A 12-inch skillet may not fit multiple sandwiches.
This recipe fit two sandwiches in my Instant Vortex Plus 6-quart and Cosori 5.8-quart air fryers. Perhaps a third could have fit with slightly different-shaped bread slices.