Fully cook your bacon in the microwave and drain off any grease.
Core your apples and cut into thin slices.
Toast bread and grate the cheese.
Turn on oven to low broil OR heat a griddle to about 350 degrees.
On a baking sheet, layer bread with bacon, then the apple, and finally the cheese. Broil until the cheese has melted. (You may want to cover sandwiches with a pot lid to seal in the heat if doing them on the griddle).