I have made meatloaf tons of different ways. I had 1/2 jar of spaghetti sauce left over from the kids lunch, so I made this version. Sometimes meatloaf tastes like dog food... fortunetly this version has always tasted good for us. The grated onion keeps it moist (especially if you are using lean hamburger) and the spaghetti sauce gives it good flavor.
1 pound ground beef
1/2 grated onion
1/2 cup ground rolled oats (you can do this in the blender or Magic Bullet)
1/2 jar spaghetti sauce, divided
1/2 tsp salt
1/4 tsp pepper
Mix ground beef, onion, egg, oats, 1/2 cup spaghetti sauce, salt and pepper. Form into loaf and bake covered for 45 minutes at 350. Uncover and spoon remaining sauce over loaf. Return to oven and bake 15-25 minutes at 375, or until meat is cooked.