Preheat the oven to 350°F (175°C) and lightly coat a shallow, oven-safe baking dish with cooking spray or a little oil.
In a shallow dish, combine the flour and Parmesan cheese, then stir in the black pepper and paprika (or garlic powder) until evenly mixed.
Place the beaten egg whites in a separate shallow bowl.
Dip each chicken breast first into the beaten egg whites, letting any excess drip off, then dredge thoroughly in the flour–Parmesan mixture to coat evenly.
Arrange the coated chicken breasts in a single layer in the prepared baking dish, leaving space between pieces.
Bake uncovered for 45 minutes to 1 hour, depending on the size of the breasts, until the coating is browned and an instant-read thermometer inserted into the thickest part reads 165°F (74°C) or juices run clear.
Remove from the oven and let rest a few minutes before serving.