Preheat the oven to 375 degrees. Line a rimmed baking sheet with foil and place a baking rack on top of that. Spray the rack with non-stick spray. Set aside. Alternatively, you can just spray the foil and bake the meatballs on it that way.
I like to use lean ground beef for most recipes, unless it's burgers or meatballs. I think those two need a bit of the fat found in ground beef. For this recipe, I used one pound of an 85% lean ground beef. Place ground beef in large bowl. Add in two tablespoons of the finely diced onions, 2 cloves minced garlic, 1/4 teaspoon black pepper, 1 1/2 teaspoon of freeze-dried basil and oregano. If using fresh, use a heaping tablespoon of each herb. If using dried, follow the freeze-dried amounts. Again, I do not add salt, if you want to, add about 1/2 to 1 teaspoon, according to your tastes.
Beat one egg in a small bowl and add it into the bowl with the ground beef and seasonings. Lastly, add about 1/4 cup uncooked oatmeal (or panko bread crumbs) to the bowl.
Using clean hands (I find this is easiest so that you don't overwork the meat) mix everything until just combined. I like to make the meatballs about two inches in diameter, so from one pound of meat, I can get about 18 meatballs. Roll the meatballs and place on prepared baking sheet.
Bake in oven for 12-15 minutes - you want to undercook them slightly. Remove from oven and place in saucepan with sauce. Gently mix in and cover and let simmer for at least an hour.
Cook your spaghetti noodles according to the package directions and drain. Serve with the sauce and meatballs. Don't forget the Parmesan cheese and garlic bread!