I don't know where I got this meatloaf recipe. My guess is that it was in an ad for Karo® corn syrup in Good Housekeeping Magazine; probably back in the late 70s or early 80s. I have it hand-written on an index card, which has numerous spill marks all over it.
My poor tired recipe card. It resembles a lot of others too.
I eventually laminated. When I pulled it out to compose it here, I found that I had never written the apple on the recipe card (horrors!), but, I know it's supposed to be there and have always used it. This recipe is not a traditional meatloaf recipe. It is not hot and spicy, but is somewhat sweet and moist. This was somewhat of a culture shock to my kids when grandma made it and later when they went off to college and were exposed to the more traditional recipe in the dining hall. They do not care for the traditional meatloaf, but this recipe, they adore.
Mustard: I've always used plain, ordinary, French's.
Bread crumbs: I don't use manufactured bread crumbs, I just dice a couple of slices of bread. A great way to use often unwanted end slices. I just chop up a couple of end slices of whatever I have on hand.
Onion: I don't think I ever measure it, I think I just use a small or medium-sized onion.
Apple/Nutmeg: This tastes so great with an apple and the nutmeg in it. If I don't have an apple, I don't add the nutmeg. It just does not taste the same.
Beef: Once the beef is added, it's actually best to mix by hand.