Slice the eggplants into 1/4-inch thick rounds. Sprinkle salt over the slices and let them sit for about 30 minutes to draw out excess moisture and bitterness. Rinse the slices under cold water and pat them dry with paper towels.

Preheat your oven to 375°F (190°C).

Line a baking sheet with parchment paper and arrange the eggplant slices in a single layer. Brush each slice lightly with olive oil and bake for about 25-30 minutes, flipping halfway through, until golden brown and slightly crispy.

In a large baking dish, spread a thin layer of marinara sauce on the bottom. Start layering with eggplant slices, then add a layer of mozzarella cheese, another layer of marinara, and a sprinkle of Parmesan. Repeat the layers until all ingredients are used, finishing with a layer of marinara and the remaining mozzarella and Parmesan.

Sprinkle dried oregano, dried basil, and black pepper over the top layer of cheese.

Cover the baking dish with aluminum foil and bake for 30 minutes. Remove the foil and bake for an additional 15-20 minutes, or until the cheese is bubbly and golden.

Let the casserole cool for about 10-15 minutes before serving. Garnish with fresh basil leaves if desired.