Combine ground beef, breadcrumbs, Parmesan, egg, parsley, and a pinch of salt and pepper in a bowl. Mix gently until just combined.

Form the mixture into 12–14 golf-ball-sized meatballs.

Heat olive oil in a large skillet over medium-high heat. Add meatballs in a single layer and brown on all sides, about 6–8 minutes total.

Transfer the browned meatballs to a plate and lower the heat to medium.

Add sliced bell peppers to the skillet and sauté for 2–3 minutes until slightly softened.

Stir in heavy cream, garlic powder, and onion powder. Bring sauce to a gentle simmer.

Return meatballs to the skillet, spoon sauce over them, and simmer for 4–6 minutes until sauce thickens slightly and meatballs are cooked through.