Bake potatoes until done. Cut potatoes in half lengthwise and remove center, leaving a 1/4" around sides. Mash potatoes, add milk, butter, salt and pepper to taste. Place 1/2 slice of cheese in bottom of potato shell. Spoon mashed potatoes into shells and top with a pat of butter, bacon bits and 1/3 slice of cheese. Bake on a cookie sheet at 350 to 400 degrees until cheese is melted.