Sprinkle eggplant evenly on both sides with salt and 1/4 teaspoon pepper.
Whisk egg whites in a shallow bowl until frothy. Set aside.
Combine breadcrumbs, Parmesan cheese, Italian seasoning, and remaining 1/4 teaspoon pepper in a bowl.
Dip eggplant slices in egg whites, and dredge in breadcrumb mixture. Arrange on a wire rack coated with cooking spray in an aluminum foil-lined 15- x 10-inch jellyroll pan. Lightly coat eggplant slices evenly on both sides with cooking spray.
Bake at 375 for 20 to 25 minutes or until golden brown and eggplant is tender, adding split bread halves to oven during the last 5 minutes.
Spread pasta sauce evenly on cut sides of bread. Arrange eggplant on bottom half of bread; sprinkle with cheese.
Broil 6 inches from heat 2 minutes or until cheese melts. Cover with top half of bread.
Cut into 6 sandwiches, and serve with pasta sauce, if desired.
*1 cup Italian breadcrumbs may be substituted for panko breadcrumbs.