Add the red onions, garlic, parsley, Italian seasoning, paprika, garlic powder, breadcrumbs, egg, salt, and pepper to a food processor. Pulse until finely chopped and well combined.

Transfer the mixture to a large bowl, add the ground beef, and gently mix with your hands until just combined.

Using a small ice cream scoop, portion the meatballs. Lightly toss each one from hand to hand to release any trapped air.

Heat olive oil in a large skillet over medium heat and brown the meatballs in batches until golden on all sides (not cooked through). Set them aside.

In a Dutch oven, heat olive oil and sauté the chopped onion until soft and fragrant. Stir in Italian seasoning, tomato sauce, salt, and garlic powder. Let it simmer gently.

Add the meatballs back into the sauce, then pour in the heavy cream and add fresh basil. Simmer together until the meatballs are cooked through and the sauce is rich and silky.

Cook your pasta in well-salted water. Spoon the meatballs and sauce generously over the pasta and finish with Parmesan and parsley.