Pulse onion, carrot, and celery in food processor until finely chopped and set aside.
Process garlic and pancetta until finely chopped.
Heat olive oil in large heavy pot over medium heat and cook pancetta mixture 3-4 minutes until golden.
Add soffritto and cook 5-6 minutes until softened.
Add ground beef, Italian sausage, and red pepper flakes and cook undisturbed 3-4 minutes.
Break up meat and brown 8-10 minutes total.
Push meat aside, add tomato paste to empty space, and cook 2 minutes stirring frequently.
Pour in red wine and simmer 5-6 minutes until reduced by half, scraping up browned bits.
Add rosemary, thyme, bay leaves, parmesan rind, crushed tomatoes, and 1 1/2 cups chicken broth.
Reduce heat to low and simmer 90 minutes, stirring every 15-20 minutes and adding broth if needed.
Remove herb sprigs, bay leaves, and parmesan rind.
Stir in heavy cream and grated parmesan and simmer 2-3 minutes.
Season with salt and pepper to taste.
Cook pappardelle in salted boiling water until al dente and reserve 1 cup pasta water before draining.
Toss pasta with sauce, adding reserved pasta water as needed to reach desired consistency.
Serve with extra parmesan.