Coat the loaf with ketchup or bacon (optional): Spread 1/4 cup of the ketchup mixture over the meatloaf (reserve the other 1/4 cup for later). Alternatively, drape the loaf with bacon slices. Bake for 45 minutes: Bake the meatloaf for 45 minutes, then spread with the remaining 1/4 cup of ketchup, if using. Bake for another 10 to 15 minutes: Bake the loaf for another 10 to 15 minutes (about 1 hour total), until the middle of the loaf registers at least 155°F on an instant-read thermometer. Cool 15 minutes before serving: Let the loaf cool for at least 15 minutes before serving.