In a large mixing bowl, combine ground beef, panko breadcrumbs, egg, Parmesan cheese, milk, garlic powder, onion powder, dried oregano, 1/2 tsp salt, and 1/4 tsp black pepper. Mix gently with your hands until just combined; do not overmix.

Roll the mixture into small, bite-sized meatballs, about 1-inch in diameter. You should get approximately 30-35 meatballs.

Heat 1 tablespoon of olive oil in a large pot or Dutch oven over medium-high heat. Add meatballs in batches and sear until browned on all sides, about 3-5 minutes per batch. They don't need to be cooked through at this stage. Remove browned meatballs and set aside on a plate.

In the same pot, reduce heat to medium. Add the remaining 2 tablespoons of olive oil. Add the diced onion, carrots, and celery. Sauté for 5-7 minutes, until the vegetables begin to soften.

Add the minced garlic and cook for another minute until fragrant, being careful not to burn it.

Stir in the crushed tomatoes, chicken or beef broth, dried basil, dried oregano, and the bay leaf. Season with 1/2 tsp salt and 1/4 tsp black pepper. Bring the soup to a gentle boil.

Carefully add the seared meatballs back into the pot. Reduce heat to low, cover, and simmer for 15-20 minutes, allowing the flavors to meld and the meatballs to cook through.

Stir in the small pasta. Increase heat to medium and cook uncovered according to package directions, usually 8-10 minutes, or until the pasta is al dente. Ensure to stir occasionally to prevent pasta from sticking.

Remove and discard the bay leaf. If using, stir in the fresh spinach and cook just until wilted, about 1-2 minutes.

Taste and adjust seasoning as needed. You might want to add more salt or pepper.

Ladle the hot meatball soup into bowls. Garnish generously with fresh chopped parsley and a sprinkle of grated Parmesan cheese.