01 - Preheat oven to 425°F. Line two large baking sheets with parchment paper.
02 - Lay eggplant slices on a rack or paper towels. Sprinkle both sides with salt and let sit for 30 minutes to draw out bitterness. Pat dry with paper towels.
03 - In a shallow bowl, combine breadcrumbs, 1/2 cup Parmesan, oregano, garlic powder, and black pepper. In a separate bowl, whisk eggs with milk.
04 - Dip each eggplant slice into the egg mixture, then coat in the breadcrumb mixture, pressing gently to adhere.
05 - Arrange eggplant slices in a single layer on prepared baking sheets. Spray or brush lightly with olive oil. Bake for 20 minutes, flip slices, then bake another 10-15 minutes until golden and crisp.
06 - Reduce oven temperature to 375°F.
07 - Spread 1/2 cup marinara sauce in the bottom of a 9x13-inch baking dish. Layer half the baked eggplant slices over the sauce. Spoon 1 cup marinara sauce over the eggplant, then sprinkle with 1 cup mozzarella and 1/4 cup Parmesan.
08 - Repeat with remaining eggplant, sauce, mozzarella, and Parmesan. Cover loosely with foil and bake for 20 minutes.
09 - Remove foil and bake an additional 10 minutes until cheese is bubbly and golden. Let rest 10 minutes before serving. Garnish with fresh basil if desired.