Make the Sauce:
Add heavy cream, cream cheese, Parmesan, garlic, Italian seasoning, salt, and pepper into the Crockpot. Whisk until combined.
Add the Chicken:
Place chicken breasts into the sauce. Cover and cook on LOW for 4–5 hours or HIGH for 2–3 hours, until tender.
Shred the Chicken:
Remove chicken, shred with two forks, and return it to the sauce.
Add Tortellini:
Stir in cheese tortellini and butter. Cover and cook for 20–30 minutes on LOW until the pasta is soft and sauce thickens.
Add Spinach (Optional):
Stir in baby spinach just before serving for added color and nutrients.
Serve:
Garnish with fresh parsley and extra Parmesan. Serve hot.