01 -
Place the chicken in the bottom of a 6-quart slow cooker. Pour in the marinara, broth, Italian seasoning, garlic powder, onion powder, salt, and pepper. No need to stir much. The chicken just needs to be mostly covered.
02 -
Cover and cook on LOW for 4 to 5 hours or on HIGH for 2 to 3 hours, until the chicken shreds easily with a fork.
03 -
Remove the breasts, shred them with two forks, and return the meat to the pot. The broth will look thin at this stage. That is normal.
04 -
Drop in the cubed cream cheese and stir until it melts completely into the tomato broth. This takes a minute or two of vigorous stirring.
05 -
Stir in the uncooked pasta and push it under the liquid. If the surface looks dry, add 1/2 cup of hot water or extra broth. Cover and cook on HIGH for 30 to 40 minutes, stirring once halfway through, until the penne is tender but still has a little bite.
06 -
Sprinkle the shredded mozzarella and grated Parmesan over the surface. Cover for 5 minutes without lifting the lid so the cheese melts into a gooey blanket. Garnish with chopped parsley and serve straight from the pot.