Make the Meatballs In a large bowl, combine ground beef, breadcrumbs, Parmesan, parsley, egg, garlic, salt, pepper, and oregano. Mix gently until combined (do not overmix). Shape into 1-inch balls and place on a tray.
Brown the Meatballs Heat olive oil in a skillet over medium heat. Brown the meatballs on all sides (they don’t need to be fully cooked through). Transfer to a plate and set aside.
Prepare the Sauce In the same skillet, add more olive oil if needed. Sauté onion until translucent, then add garlic and cook until fragrant. Stir in crushed tomatoes, tomato paste, basil, oregano, and sugar. Season with salt and pepper, then let simmer for 10 minutes.
Combine Meatballs and Sauce Add browned meatballs into the sauce. Cover and simmer for 20–25 minutes, until meatballs are fully cooked and tender.
Cook the Pasta Boil water with salt. Add spaghetti and cook until al dente (usually 8–10 minutes). Drain, reserving a little pasta water if needed to loosen sauce later.
Assemble the Dish Plate spaghetti on serving dishes. Top with meatballs and sauce. Garnish with fresh herbs and Parmesan.