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.