Heat oil in a large pot over medium-high heat. Season chicken breasts with salt, pepper, Italian seasoning, and garlic powder. Sear for 5 minutes on the first side, then flip and cook another 3 to 4 minutes. Remove to a plate. Chicken will not be fully cooked yet.

In the same pot, add diced onion and minced garlic. Stir for 2 to 3 minutes until softened and fragrant, scraping up any browned bits from the bottom.

Pour in marinara sauce and water. Bring to a gentle boil, then reduce heat to medium-low. Add seared chicken and dried pasta. Stir to distribute evenly. Cover and cook for 10 to 15 minutes, stirring occasionally, until pasta is tender and chicken reaches 165 degrees F.

Remove from heat. Stir in Parmesan and 1/4 cup of the mozzarella until melted into the sauce. Add a splash of water if the sauce is too thick.

Transfer to a 9x13 inch baking dish. Spread remaining 3/4 cup mozzarella evenly over the top. Place under a preheated broiler for 2 to 3 minutes until cheese is melted and lightly golden. Watch closely.

Let rest for 1 to 2 minutes. Garnish with torn fresh basil, chopped parsley, and a sprinkle of dried Italian seasoning. Serve immediately.