01 - Preheat oven to 400°F. Line two baking sheets with parchment paper and lightly oil or spray with olive oil.
02 - Arrange eggplant slices on a wire rack or paper towels. Sprinkle both sides with kosher salt and let sit for 20 minutes to draw out excess moisture. Pat dry with paper towels.
03 - Place flour in one shallow bowl, beaten eggs in a second, and mix breadcrumbs, Parmesan, oregano, and black pepper in a third.
04 - Dredge each eggplant slice in flour, dip in egg, then coat with breadcrumb mixture. Place coated slices on prepared baking sheets.
05 - Lightly spray or drizzle olive oil over the breaded slices. Bake for 20 minutes, flipping halfway through, until golden and crisp.
06 - Reduce oven temperature to 375°F. In a 9x13-inch baking dish, spread 1/2 cup marinara sauce. Layer half the baked eggplant slices over the sauce. Top with half the remaining marinara and half the mozzarella. Repeat with remaining eggplant, sauce, and mozzarella. Sprinkle with the final 1/3 cup Parmesan.
07 - Bake, uncovered, for 20–25 minutes until cheese is bubbly and golden.
08 - Let rest 10 minutes before serving. Garnish with fresh basil if desired.