Preheat your oven to 400°F (200°C) and line a baking tray with parchment paper.
In a mixing bowl, combine ground beef, breadcrumbs, Parmesan cheese, egg, minced garlic, oregano, salt, pepper, and parsley (if using). Mix until all ingredients are well combined.
Form the mixture into small meatballs, about 1-inch in diameter, and place them on the prepared baking tray.
Bake the meatballs in the preheated oven for about 15 minutes or until browned.
While the meatballs are baking, heat olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion, carrots, and celery. Sauté for about 5 minutes, or until the vegetables are softened.
Add the broth and diced tomatoes to the pot. Bring to a simmer.
Once the meatballs are cooked, carefully add them to the soup. Stir in the small pasta and dried basil. Cook for an additional 10-12 minutes until the pasta is tender.
Taste and season with salt and pepper as needed.
Serve hot, garnished with chopped fresh basil if desired.