Preheat oven to 375 degrees.

In a large bowl, gently combine beef, onion, breadcrumbs, milk, egg, salt and pepper then press into a 9x9 baking dish.

Bake uncovered for 15 minutes, then remove and drain any excess fat.

While the meatloaf is cooking add potatoes with just enough water to cover to a pot and bring to a boil on high heat. Cook for 15 minutes.

Drain the water and add the milk, butter, salt and pepper mashing it all together until creamy.

Spread over the meatloaf and top with cheese and bacon.

Bake for and additional 15 minutes, until bacon is sizzling and cheese is bubbling and the mashed potatoes are slightly crispy.