01 - Preheat oven to 400°F. Lightly oil a baking dish large enough for chicken breasts in a single layer.
02 - Pat chicken breasts dry thoroughly and arrange evenly in the baking dish.
03 - Whisk together Caesar dressing, sour cream, 1/2 cup grated Parmesan, garlic powder, and black pepper until smooth.
04 - Spread sauce evenly over each chicken breast, ensuring thorough coverage.
05 - Sprinkle shredded mozzarella and remaining 2 tablespoons Parmesan cheese evenly over the sauced chicken.
06 - Bake for 25 to 30 minutes, until chicken is cooked through (internal temperature reaches 165°F) and cheese is golden and bubbling.
07 - Allow chicken to rest 5 minutes. Garnish with chopped parsley before serving if desired.