01 - Preheat the oven to 400°F. Lightly grease a baking dish large enough to hold the chicken breasts in a single layer.
02 - Pat chicken breasts dry with paper towels and arrange them in the prepared baking dish.
03 - In a bowl, whisk together Caesar dressing, sour cream, 1/2 cup grated Parmesan cheese, garlic powder, and ground black pepper until smooth.
04 - Spread the prepared sauce evenly over the chicken breasts, ensuring each piece is well coated.
05 - Sprinkle mozzarella cheese and 2 tablespoons grated Parmesan cheese evenly across the top.
06 - Bake in the preheated oven for 25 to 30 minutes, or until chicken reaches an internal temperature of 165°F and the surface is golden and bubbling.
07 - Let chicken rest for 5 minutes, then garnish with chopped fresh parsley if desired before serving.