Butter 2 bread slices. Cook 1 bacon slice in heavy skillet; remove and keep warm. Pour off excess fat. Break an egg into a measuring cup, season with salt and pepper and beat lightly with a fork. Pour egg into skillet; do not stir. When it is set on bottom, turn like a pancake and remove skillet from heat. Lift egg with spatula to one of the bread slices. Dot with ketchup. Add bacon, crumbled. Top with other bread slice and serve immediately. You can make 3 egg fillings at a time.