How to Make It
Sprinkle 2 tablespoons plus 2 teaspoons salt on both sides of eggplant rounds, and place on a wire rack lined with paper towels. Let liquid drain from eggplant 30 minutes.
Meanwhile, preheat broiler to high with oven rack 6 inches from heat. Heat 3 tablespoons olive oil in a large skillet over medium-high. Add breadcrumbs, and cook, stirring often, until lightly browned, 5 to 6 minutes. Add minced garlic, lemon zest, and thyme. Cook, stirring often, until fragrant, 1 to 2 minutes. Remove from heat, and set breadcrumb mixture aside.
Pat eggplant dry. Drizzle both sides of eggplant rounds with remaining 1 tablespoon olive oil, and sprinkle with pepper and remaining 1 teaspoon salt. Place in a single layer on a rimmed baking sheet. Broil in preheated oven until lightly golden brown, about 4 minutes per side. Let cool 10 minutes.
Reduce oven temperature to 425°F. Layer tomatoes and mozzarella slices between eggplant rounds, slightly overlapping, on baking sheet. Drizzle with marinara sauce. Sprinkle with Parmesan, top with breadcrumb mixture, and bake at 425°F until cheese is melted and golden brown, about 15 minutes. Sprinkle with basil, and serve.