01 - Preheat the oven to 400°F and lightly grease a baking dish large enough to fit the chicken breasts in a single layer.
02 - Pat the chicken breasts dry with paper towels and arrange them 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 smooth.
04 - Evenly spread the prepared sauce over each chicken breast, ensuring full coverage.
05 - Sprinkle shredded mozzarella and an additional 2 tablespoons grated Parmesan cheese over the sauced chicken breasts.
06 - Place the baking dish in the preheated oven and bake for 25 to 30 minutes, or until internal temperature of the chicken reaches 165°F and the top is golden and bubbling.
07 - Allow the chicken to rest in the dish for 5 minutes. Garnish with chopped parsley prior to serving, if desired.