Preheat your air fryer to 350°F (175°C) for 2 minutes. This helps the bread toast immediately upon contact.
Press the back of a large spoon firmly into the center of the bread slice to create a well. Do not tear through the bread.
Spread the softened butter lightly around the raised crust edges of the bread.
Place the bread carefully into the air fryer basket.
Crack the egg gently into the indentation you created.
Sprinkle the shredded cheese around the egg white, avoiding the yolk if you want it to look vibrant.
Season with a pinch of salt and pepper over the entire slice.
Cook at 350°F (175°C) for 5 to 7 minutes. Check at 5 minutes; cook longer if you prefer a firm yolk.
Remove carefully with a spatula and serve immediately.