Preheat oven to 350. Spray large 9x13 glass or ceramic baking dish with non-stick cooking spray. Set aside.
Fry bacon in strips and chop, or pre-cut and fry it. Let drain while preparing rest of the dinner.
Boil macaroni until about half done, should still be semi hard to squeeze. Rinse with cold water to stop the cooking and keep from sticking together. Set aside to drain.
In large sauce pan melt butter and add flour on medium heat, when incorporated well add milk and continue to stir until slightly thickened. Turn down flame and add cheeses one at a time stirring lightly until melted, add pepper and stir, set aside.
Pour cooled pasta into baking dish and mix in bacon pieces and cheese sauce. Top with additional sharp cheddar, Parmesan, bread crumbs, or anything that tickles your fancy. I prefer a good sharp cheddar, my hubby and boys like more bacon, go figure. Bake at 350 for 45 minutes to 1 hour, serve hot as main dish or as side.