Add meatballs, marinara, Italian seasoning, salt, and pepper to a slow cooker. Cook on Low for 3 to 4 hours.
Add cream cheese to the slow cooker and stir to combine. Stir in tortellini and top with shredded mozzarella. Cook for an additional 30 minutes to 1 hour on High.
Garnish with parsley or basil and serve.
