Preheat oven to 350 degrees. Spray an 8" x 8" x 2" baking pan with non-stick cooking spray; set aside.
Trim the ends of the eggplant, if desired, then slice the eggplant crosswise into 1/2" thick slices; set aside.
In a shallow bowl, stir together the bread crumbs, parmesan cheese and oregano. Dip the eggplant slices into the flour. Then dip them into the egg whites, then coat with bread crumb mixture.
Arrange the eggplant in the prepared pan. Bake on center rack for 20-25 minutes or until a light golden brown. When finished, remove from oven. Spoon the marinara sauce over the eggplant, sprinkle with mozzarella cheese and return eggplant to the oven for 10 minutes or until cheese is melted.
