To make it faster, cook the bacon in the microwave. Line a plate with paper towel and place the two bacon slices on it. Put another paper towel on top of the bacon and microwave it for about 3 minutes. Set it aside. Cooking it in a frying pan would also work and would be easier if making more than one sandwich.

Pre-heat an electric non-stick griddle to 300 degrees or a non-stick griddle pan over medium high heat. Assemble the sandwich by layering one slice of the cheddar, then the sliced apple, the bacon next, and then last slice of the cheddar. Close it with the second slice of bread. Grease the griddle liberally with the butter and brown the sandwich on the first side for two minutes or so. Press it down as it cooks so that it adheres together. Flip it over to brown on the other side for another two minutes or so. Cut in half and serve immediately!