01 - Preheat the oven to 400°F. Line a rimmed baking sheet with parchment paper and set aside.
02 - In a large mixing bowl, combine the ground beef, breadcrumbs, Parmesan, milk, egg, garlic, parsley, oregano, salt, and pepper. Mix gently until just incorporated — avoid overworking the mixture. Roll into 16 to 18 evenly sized meatballs and arrange on the prepared baking sheet.
03 - Bake for 15 to 18 minutes, until the meatballs are golden brown on the outside and cooked through to an internal temperature of 160°F.
04 - While the meatballs bake, heat the olive oil in a large skillet or sauté pan over medium heat. Add the diced onion and cook until softened and translucent, about 3 minutes. Stir in the garlic and cook for 1 additional minute until fragrant.
05 - Pour in the crushed tomatoes, broth, sugar, salt, and pepper. Stir to combine and bring to a gentle simmer. Let the sauce reduce and develop flavor for 7 to 8 minutes.
06 - Reduce the heat to low and stir in the heavy cream until the sauce is smooth and uniformly colored. Add the chopped basil and simmer for 2 more minutes.
07 - Transfer the baked meatballs into the skillet with the sauce. Cook together for 5 minutes over low heat, spooning the sauce over the meatballs occasionally so they absorb the flavors and heat through evenly.
08 - Serve hot, garnished with additional fresh basil leaves. Pair with pasta, steamed rice, or crusty bread to soak up the sauce.