Add chicken to crockpot: Place chicken breasts in the bottom of your slow cooker.
Add sauce + seasoning: Pour in the Mezzetta marinara sauce, sprinkle in garlic powder, onion powder, Italian seasoning, salt, and pepper. Stir a bit to coat the chicken evenly.
Slow cook: Cover and cook on Low for 6 hours or High for 3–3½ hours, until the chicken is tender and easily shreds.
Shred + stir: Shred the chicken right in the crockpot using two forks. Stir in the cream cheese until smooth and creamy.
Add pasta: Add uncooked pasta and chicken broth or water, making sure the noodles are mostly submerged in the sauce.
Cook again: Cover and cook on High for 25–35 minutes, stirring halfway through, until pasta is tender.
Top + melt: Sprinkle mozzarella and parmesan over the top. Cover for another 5–10 minutes until melted and bubbly.
Serve: Garnish with fresh basil or parsley and serve warm.