Preheat oven to 350 F. In a large bowl, combine ground beef, breadcrumbs, seasonings, egg, milk, ketchup, and worcestershire sauce. Press mixture out into a greased baking dish. Bake for 40-50 minutes.
Place potatoes into a large saucepan, cover with water and bring to a boil over medium heat. Simmer until potatoes are fork tender. Drain. Mash potatoes with butter, salt, and pepper. Evenly spread potatoes over meatloaf. Sprinkle with shredded cheddar cheese. Bake for another 20-25 minutes.