Combine parmesan and ricotta in a bowl
Brown beef & sausage with onion, celery, garlic, salt and pepper
Strain
Place a layer of meat mixture into slow cooker
Add a layer of mozzarella
Add layer of whole tomatoes
Add ricotta and parmesan mixture
Add layer of raviolli
Add layer of tomato sauce
Add layer of Italian seasoning
Repeat layers
Reserve mozzarella for final topping
Cook on low 4 - 6 hours
With 10 minutes remaining, add remaining mozzarella
Sprinkle with grated parmesan
Cover and cook remaining ten minutes
Serve and enjoy