Place the beef cubes, onion, carrots, celery, and garlic in the slow cooker.
Add the crushed tomatoes, tomato paste, beef broth, oregano, basil, bay leaves, salt, and pepper. Stir to combine everything.
Cover and cook on low for 8 hours until the beef is very tender.
Remove the bay leaves. Use two forks to shred the beef directly in the sauce, then stir to mix it evenly.
Bring a large pot of salted water to a boil. Cook the fresh pappardelle according to package directions until al dente, then drain.
Divide the pasta among four bowls. Spoon the ragu over the top. Finish with grated Parmesan and chopped parsley.