Drape bacon slices over an air fryer rack inset. Lower the rack into the air fryer basket. (If no rack, place bacon on top of aluminum foil, ensuring the bacon holds down the corners so the foil doesn't fly up when air frying).
Air fry at 400°F for 10 minutes.
Meanwhile, in a large bowl, beat eggs until smooth. Heat butter in a skillet over medium heat on the stove. Scramble eggs to your liking. Set aside.
When bacon is done cooking, carefully remove the rack from the basket. Set aside to cool.
Assemble the sandwiches: Lay out English muffins. Top the bottom half of each with a spoonful of scrambled eggs, then top with one slice of bacon (I fold the bacon in half to cover more area in the sandwich), and one slice of cheese. Add the top of the English muffin. Poke a toothpick through the center of each sandwich to hold together. Place assembled sandwiches onto air fryer baskets. If there is room, place them on top of racks that fit into the air fryer basket. If not, you can place them right into the bottom of the basket.
Air fry at 400°F for 3 minutes.
When breakfast sandwiches are done cooking, allow them to cool for a minute if you are serving immediately.
Storage Tip: If you’ll be eating these later for meal planning, allow sandwiches to cool completely before wrapping and refrigerating or freezing. Wrap in foil and refrigerate in an airtight container for up to 3 to 4 days, or freeze for up to 2 months.