Place chicken breasts in the slow cooker and sprinkle the Italian dressing mix evenly on top.
Pour in the chicken broth, cover, and cook on low for 6–7 hours or high for 3–4 hours until the chicken is tender.
Remove chicken, shred it with two forks, and return to the slow cooker.
Add cream cheese, Parmesan, and heavy cream; stir until melted and smooth.
Boil pasta until al dente, drain, and add to the slow cooker.
Stir in spinach and cherry tomatoes, season to taste, and cook for 30 more minutes.
Garnish with fresh basil before serving.
