Pat chicken dry and season both sides with Italian seasoning, garlic powder, salt, and pepper.
Spray slow cooker with non-stick spray. Place seasoned chicken in bottom.
Add butter pieces, cream cheese chunks, heavy cream, chicken broth, and minced garlic.
Sprinkle with Italian seasoning, salt, and pepper.
Cover and cook on LOW 4 hours or HIGH 2.5 hours until chicken reaches 165°F.
Remove chicken, shred with two forks.
Add Parmesan cheese to slow cooker, stir until melted and smooth.
Return shredded chicken to sauce, stir to coat. Cover, keep warm 10-15 minutes.
Cook pasta according to package directions, drain, reserve ½ cup pasta water.
Add cooked pasta to slow cooker, toss to coat. Add pasta water if needed to thin.
Serve garnished with fresh parsley and extra Parmesan.