01 - In a large bowl, combine ground beef, breadcrumbs, Parmesan, egg, garlic, milk, salt, pepper, and basil. Mix gently until just combined — avoid overmixing to keep meatballs tender.
02 - Roll the mixture into golf ball–sized meatballs, yielding approximately 16 pieces.
03 - Heat olive oil in a large skillet over medium heat. Add the meatballs and cook, turning frequently, until browned on all sides, about 6 minutes. Remove and set aside — they will finish cooking in the sauce.
04 - In the same skillet, add the chopped onion and sauté until softened, 3 to 4 minutes. Add garlic and cook for 30 seconds until fragrant.
05 - Pour in the crushed tomatoes and broth. Season with salt, pepper, and sugar if using. Simmer for 5 minutes to allow flavors to meld.
06 - Stir in the heavy cream and Parmesan cheese, then fold in the chopped basil. Nestle the browned meatballs back into the sauce.
07 - Simmer uncovered on low heat for 15 to 20 minutes, gently turning the meatballs occasionally, until they are cooked through and the sauce has thickened.
08 - Taste and adjust seasoning as needed. Garnish with fresh basil leaves and serve over pasta, rice, or alongside crusty bread.