Place the chicken breasts in the bottom of the slow cooker.
Pour the crushed tomatoes over the chicken and add the minced garlic, salt, and black pepper.
Cover and cook on low for 6 hours until the chicken reaches an internal temperature of 165°F and shreds easily.
About 20 minutes before serving, cook the pasta in a large pot of boiling water according to package directions, then drain.
Shred the chicken directly in the slow cooker with two forks and stir in the chopped basil.
Divide the pasta among four bowls, top each with the chicken and sauce mixture, and sprinkle with Parmesan cheese.