01 - Preheat oven to 400°F. Lightly grease a baking dish large enough to fit the chicken breasts in a single layer.
02 - Pat chicken breasts dry and arrange them 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 homogenous.
04 - Spread the prepared sauce evenly over all chicken breasts to fully coat each piece.
05 - Sprinkle shredded mozzarella and remaining 2 tablespoons Parmesan cheese over the sauce-covered chicken.
06 - Place dish in preheated oven and bake for 25 to 30 minutes, until chicken is cooked through with an internal temperature of 165°F and the top is golden and bubbly.
07 - Let chicken rest 5 minutes out of the oven. Garnish with chopped fresh parsley before serving if desired.