• Halve the apple. Remove the core from the center with a sharp paring knife. If you’d like to peel them, do so, but the skin is high in fiber and nutrients.
• Slice the apples into thin wedges.
• Spread mayonnaise in a thin layer on one side of each bread slice. If you use butter, use very soft butter, or brush melted butter on one side.
• Place the bread on a parchment paper-covered air fryer basket with the mayonnaise side down. Add the slice of American cheese.
• Arrange the apple slices on top of the cheese.
• Air fry at 350°F for 4-5 minutes until the top is golden brown. Flip the sandwich halfway through. Continue to air fry for 4-5 more minutes until the second side is golden.

Stovetop Instructions

• Assemble the sandwich as described above. Use a nonstick skillet over medium heat. Carefully place the sandwiches in the skillet. You should hear a sizzle. When the sizzling slows down or stops, the sandwich is ready to flip. It usually takes 4-5 minutes, depending on your heat level.
• Carefully flip the sandwich with a pancake turner and brown the other side of the bread. Once it’s browned, remove it from the pan and serve.