Lightly grease the slow cooker with cooking spray or olive oil.
Place the chicken breasts in a single layer in the slow cooker.
Sprinkle with salt, pepper, paprika, garlic powder, onion powder, and Italian seasoning.
Add the minced garlic, diced tomatoes, tomato paste, and chicken broth.
Cover and cook on LOW for 4 to 5 hours or HIGH for 2 to 3 hours.
Remove the chicken and keep warm.
Whisk the heavy cream and Parmesan cheese into the sauce until smooth.
Return the chicken to the slow cooker and spoon the sauce over the top.
Cover and cook for another 15 to 20 minutes until the sauce is creamy and slightly thickened.
Stir in the fresh basil just before serving.
Garnish with additional basil or parsley.