01 - Preheat the oven to 400°F. Lightly grease a 9x13-inch baking dish with cooking spray or a small amount of oil.
02 - Pat chicken breasts dry with paper towels. Season both sides generously with salt and pepper. Arrange in a single layer in the prepared baking dish.
03 - In a medium bowl, combine Caesar dressing, sour cream, 1/3 cup Parmesan cheese, and garlic powder. Whisk until smooth and well blended.
04 - Spread the Caesar sauce mixture evenly over the top of each chicken breast, covering completely.
05 - Sprinkle shredded mozzarella cheese and remaining 1/4 cup Parmesan cheese evenly over the sauced chicken. Add Italian herbs if using for additional flavor.
06 - Bake for 25 to 30 minutes, or until chicken reaches an internal temperature of 165°F and the cheese topping is golden brown and bubbly.
07 - Remove from oven and let rest for 5 minutes to allow juices to redistribute. Garnish with fresh chopped parsley if desired and serve warm.