Boil a large pot of salted water, add penne pasta and cook according to package instructions (9-11 mins) until al dente. Reserve ½ cup of pasta water, drain and set aside.

In a skillet, heat olive oil over medium-high heat. Season diced chicken with salt and pepper, add to skillet and sauté for 5-7 minutes until browned and cooked through.

Lower heat, pour in marinara sauce, add Italian seasoning and garlic powder, stir and simmer gently for about 2-3 minutes until heated through.

Incorporate cooked penne pasta, reserved pasta water, and shredded Parmesan cheese, mix thoroughly and cook for an additional 4-5 minutes until cheese melts.

Remove from heat, sprinkle mozzarella cheese over the top, cover and let sit for 5 minutes to melt.

Serve hot, optionally garnishing with extra Parmesan or fresh herbs.