Step 1: Prepare the eggplant: Peel the eggplants (optional) and slice into 1/4-inch thick rounds. Lay them in a single layer on baking sheets or racks and sprinkle generously with 1 tablespoon of salt. Let them sit for at least 30 minutes, or up to an hour, until beads of moisture appear. Blot the eggplant slices thoroughly dry with paper towels.
Step 2: Set up the breading station: Prepare three shallow dishes. In the first, place the all-purpose flour. In the second, whisk the 4 eggs until well beaten. In the third, combine the seasoned breadcrumbs, 1/2 cup grated Parmesan cheese, 1/4 cup chopped fresh parsley, and 1/2 teaspoon black pepper.
Step 3: Bread the eggplant: Dip each dried eggplant slice first into the flour, shaking off any excess. Then, dip into the beaten egg, ensuring it's fully coated. Finally, dredge it in the breadcrumb mixture, pressing lightly so the breadcrumbs adhere well on both sides. Place the breaded slices on a clean baking sheet or wire rack. Repeat until all eggplant slices are breaded.
Step 4: Bake the eggplant: Preheat your oven to 400°F (200°C). Lightly brush both sides of the breaded eggplant slices with olive oil. Arrange them in a single layer on baking sheets (you may need to do this in batches). Bake for 15-20 minutes, flipping halfway through, until golden brown and tender. Allow to cool slightly.
Step 5: Assemble the eggplant parmesan: Lightly grease a 9x13 inch baking dish with olive oil. Spread about 1 cup of marinara sauce evenly on the bottom of the dish. Arrange a single layer of baked eggplant slices over the sauce. Top with about one-third of the remaining marinara sauce, then sprinkle with some grated Parmesan, and cover with slices or shreds of fresh mozzarella. Repeat these layers: eggplant, sauce, Parmesan, mozzarella, until you run out of ingredients, ending with a generous layer of sauce, mozzarella, and Parmesan.
Step 6: Bake to golden perfection: Cover the baking dish loosely with aluminum foil (you can spray the underside of the foil with non-stick spray to prevent cheese from sticking). Bake for 30 minutes. Remove the foil and continue baking for another 15-20 minutes, or until the cheese is melted, bubbly, and golden brown, and the sauce is simmering around the edges.
Step 7: Rest and serve: Once out of the oven, let the eggplant parmesan rest for 10-15 minutes before slicing and serving. This resting period helps the layers set. Garnish with fresh basil leaves before serving.