In a large bowl, mash together egg, cream, and bread until a smooth paste forms. Add beef, onion, fresh parsley, dried oregano, 1 teaspoon salt, and 1/2 teaspoon pepper.
Using a strong rubber spatula or your hands, mix well. Working with 1 heaping tablespoon at a time, roll the meat mixture into 1-inch balls and place on a baking sheet.
In a large skillet over medium heat, heat olive oil. Add meatballs and cook, turning occasionally until brown on all sides, about 10 minutes. Remove from pan and place on a paper-lined plate.
To make the sauce and pasta:
In a Dutch oven or large saucepan over medium-high heat, heat oil until shimmering. Add garlic cloves and sauté until browned, stirring occasionally to prevent scorching, about 3 to 4 minutes. Remove garlic and discard.
Stir in crushed tomatoes, diced tomatoes and their juice, sugar, basil, oregano, and salt and pepper to taste (I like 1/2 teaspoon salt and 1/4 teaspoon pepper).
Add meatballs to the pan, reduce heat to medium, and simmer uncovered until flavors have blended and meatballs reach an internal temperature of 155 degrees on an internal thermometer, about 10 to 15 minutes.
While the sauce is simmering, bring 4 quarts of water and 1 tablespoon salt to a boil. Add spaghetti and cook until al dente, about 10 minutes. Drain pasta well.
Serve pasta topped with tomato sauce and meatballs, garnishing with grated parmesan, if desired.
White bread: This is key to achieve the best meatball consistency. Combine into a mash with the egg and cream to form a panade before mixing with the beef and herbs to ensure a juicy and tender texture.
Ground beef: Ground bison, lamb, or pork would also work wonderfully; just skip super-lean chicken or turkey.
Onion: To avoid biting into large chunks of onion in your meatballs, finely chop before adding to the beef mixture.
Sugar: This is an optional sauce ingredient; I prefer just a pinch to balance out the acidity in the canned tomatoes. Sweeten to taste or feel free to omit.
Spaghetti: While this is the most traditional meatball pairing, bucatini, linguine, or fettuccine can stand in. Avoid angel hair which is too delicate to stand up to the meatballs.
Yield: This recipe makes 8 servings of meatball-topped saucy spaghetti with 2 ounces of pasta each.
Storage: Store leftovers covered in the refrigerator for up to 4 days.
Make ahead: The meatballs and sauce can be made up to 3 days in advance (store them together in the refrigerator). The pasta can be cooked, cooled, and stored in the refrigerator one day in advance. Rinse with very hot water before stirring into the hot sauce.
Freezer: Get a jump on this recipe by mixing up the meatballs in advance to freeze and enjoy later; or assemble a double batch, half to enjoy now and half to freeze for later. Scoop, cook, cool, and line the meatballs in a single layer on a baking sheet. Place in the freezer for 1 hour, or until solid. Transfer to a freezer-safe container, label, date, and keep for up to one month. To reheat, place on a baking sheet, cover with foil, and bake in a 300-degree oven for 15 minutes, or until heated through.
Oven-baked meatballs: If you prefer to bake rather than pan-fry the meatballs, adjust two oven racks to the upper-middle and lower-middle positions and preheat the oven to 400 degrees. Prepare two baking sheets with parchment paper. Place formed meatballs onto the baking sheet about 2 inches apart and bake until browned and crispy, about 15 to 20 minutes, or until an internal thermometer reads 155 degrees for 15 seconds.