01 - Preheat the oven to 400°F. Lightly grease a 9×13-inch baking dish with butter or nonstick spray.
02 - Pat the chicken breasts dry with paper towels and arrange them in a single layer in the prepared baking dish.
03 - In a mixing bowl, combine the Parmesan cheese, sour cream, minced garlic, melted butter, chopped parsley, dried Italian herbs, salt, and black pepper. Stir until well blended. Add the crushed red pepper flakes if desired.
04 - Spread the garlic Parmesan mixture evenly over the top of each chicken breast, covering the surface completely.
05 - Sprinkle the panko breadcrumbs evenly over the coated chicken breasts to form a crisp, golden crust.
06 - Bake in the preheated oven for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the topping turns golden brown.
07 - For a crunchier finish, switch the oven to broil and cook for an additional 2 to 3 minutes, watching closely to prevent burning.
08 - Remove the dish from the oven and let the chicken rest for 5 minutes. Garnish with additional chopped parsley and serve warm.