01 - In a large bowl, combine breadcrumbs and milk. Let soak for 2 minutes to absorb liquid.
02 - Add ground beef, egg, Parmesan, garlic, parsley, salt, and pepper to the breadcrumb mixture. Mix gently until just combined—do not overmix to maintain tenderness.
03 - Shape mixture into 16 equal-sized meatballs, rolling gently between palms to form uniform spheres.
04 - Heat 1 tablespoon olive oil in a large skillet over medium heat. Add meatballs in batches, browning on all sides for about 5–6 minutes total. Remove and set aside—interior does not need to be fully cooked.
05 - In the same skillet, add remaining tablespoon olive oil. Sauté onion until soft and translucent, 3–4 minutes.
06 - Add minced garlic and cook for 1 minute until fragrant, being careful not to burn.
07 - Stir in crushed tomatoes, oregano, basil, red pepper flakes, sugar, salt, and pepper. Simmer for 5 minutes to blend flavors.
08 - Return browned meatballs to the sauce, cover, and simmer on low heat for 20–25 minutes, turning once halfway through, until meatballs are cooked through and sauce has thickened.
09 - Serve hot over spaghetti, topped with fresh basil leaves and extra grated Parmesan, or accompany with crusty bread for dipping.