Fill a large pot with water and bring it to a rolling boil.
Make the sauce: In a large wide, saute pan, heat the olive oil over medium heat. Add the onions and garlic and season with salt and pepper. Cook until the onions are tender, 10 to 15 minutes, and then add the plum tomatoes, sugar, and oregano. Stir to blend and then pour in the canned tomatoes and their juices. Cook, stirring from time to time, until it comes to a simmer, about 5 minutes, to allow the ingredients to meld together. Taste for seasoning. Lower the heat and let the sauce continue to cook as you make the meatballs. Season to taste with salt and pepper.
Make the meatballs: Put the beef in a large bowl and spread it all over the bottom of the bowl and up the sides a little. This will help you to distribute the seasoning evenly over the meat. Sprinkle the meat with the salt and add the bread crumbs, Parmesan cheese, parsley, and red pepper flakes. Use your hands to mix all of the ingredients together. Work in 1 of the eggs with your hands. Roll 1 small ball (about 11/2 to 2 inches in diameter).
Taste test: In a small skillet, heat 1 teaspoon of the canola oil over high heat. When the oil begins to smoke lightly, shut off the heat (to avoid splattering), and add the meatball. Put the heat back on high and brown on all sides for a few minutes until cooked but still pink in the middle. Taste for seasoning and texture. If too moist, add more bread crumbs. If too dry, add another beaten egg or a splash of water. Adjust the salt and red pepper flakes, if needed, as well. Roll the remaining meat into 11/2-inch diameter meatballs; you should have about 20.
Cook the meatballs: Heat a large skillet over high heat and add the remaining canola oil. When the oil begins to smoke lightly, shut off the heat and add the meatballs in a single layer, spreading them apart somewhat so they have a chance to brown instead of steaming. Put the heat back on high and turn the meatballs to brown them on all sides. Cook to medium-rare, 3 to 5 minutes. Squeeze the sides of 2 meatballs between your thumb and index finger to make sure they are still tender in the center. Use a slotted spoon or spatula to remove them from the pan and transfer them to a tray lined with a kitchen towel to drain any excess grease.
Cook the pasta: Season the boiling water with salt until it tastes like seawater. Bring the water back up to a boil. Add the pasta to the pot and cook, stirring occasionally with a slotted spoon to make sure it doesn't clump or stick to the bottom as it cooks, until al dente, 8 to 10 minutes. Drain the pasta in a colander, reserving about 1 cup of the cooking liquid.
Serve the meatballs: Meanwhile, once you drop the pasta in the water, add the meatballs to the sauce and simmer over very low heat, 3 to 5 minutes. Shut off the heat and allow the sauce and meat to rest as your pasta finishes cooking. Pour off any excess grease in the skillet used to brown the meatballs, add a ladle of sauce, and warm the pan over low heat. Stir to catch any browned bits of meat in the skillet. After a few minutes, pour that sauce back in with the rest. Stir in a little of the reserved pasta cooking liquid if needed to thin. Transfer the sauce and meatballs to a large bowl and toss in half of the cooked pasta. Add about 3/4 cup of the Parmesan cheese. Stir in the remaining pasta. Serve with the remaining cheese in a bowl on the side.
Old-school tip: Why did our grandmothers stew the sauce and meatballs on the stove all afternoon? It does enrich the sauce when the meat stews in it all afternoon but the meatballs are always way more cooked than need be. I like to cook my meatballs the way I eat my hamburgers, medium-rare to medium. Also, why put the pasta in a bowl and then ladle the sauce over the top? Stirring the sauce and pasta together first allows the pasta to absorb the flavors of the sauce. So, if you can resist temptation, let the pasta sit in the sauce, heat off, for a few minutes before digging in.
Recipe courtesy of Alex Guranaschelli's cookbook: Old School Comfort Food: The Way I Learned to Cook