01 - Preheat oven to 400°F. Lightly grease a baking dish large enough to arrange chicken breasts in a single layer.
02 - Pat chicken breasts dry with paper towels and place evenly in the prepared baking dish.
03 - In a mixing bowl, whisk together Caesar dressing, sour cream, 1/2 cup grated Parmesan cheese, garlic powder, and black pepper until thoroughly combined.
04 - Spread the creamy sauce evenly over each chicken breast, ensuring complete coverage.
05 - Sprinkle shredded mozzarella cheese and 2 tablespoons grated Parmesan cheese evenly over the sauced chicken.
06 - Bake uncovered in the preheated oven for 25 to 30 minutes, or until chicken reaches an internal temperature of 165°F and the cheese topping is golden and bubbling.
07 - Allow chicken to rest for 5 minutes. Garnish with chopped parsley before serving if desired.