In a large skillet over medium-high heat, cook the ground beef until browned, breaking it apart as it cooks.
Transfer the cooked ground beef to a 6-quart slow cooker. Add carrots, celery, onion, crushed tomatoes, beef broth, Italian seasoning, salt, pepper, cannellini beans, and kidney beans. Stir well.
Cover and cook on LOW for 6 hours or HIGH for 4 hours.
About 30 minutes before the soup is done, stir in the ditalini pasta. Cover and cook for an additional 30 minutes or until the pasta is tender.
Taste the soup and adjust seasoning if necessary.
Serve the soup in bowls, topped with grated Parmesan cheese.
Notes
Feel free to customize this soup by adding your favorite vegetables or adjusting the seasoning to suit your taste.