In a large skillet, drizzle olive oil and heat at med-high heat. Add chicken, Italian seasoning, and garlic powder. Cook about 5 minutes, until chicken is mostly cooked through (it will fully cook later). Move to a plate.

Add onion and garlic to the pot and cook 2-3 minutes, until soft. Pour in marinara. Fill up empty sauce jar with water and add it to the pot. Bring to a boil, then reduce to medium heat.

Add chicken and pasta, stir, and cover. Cook for 12-15 minutes, until pasta is soft. Stir in Parmesan and 1/4 cup of mozzarella.

Sprinkle remaining 3/4 cup mozzarella on top and cook another 2-3 minutes, until cheese is melted.

Sprinkle with additional Italian seasoning and parsley.