Preheat your oven to 450°F. Make sure to evenly space out two oven racks to accommodate the baking sheets. This allows for optimal roasting of the eggplant.
Lay the eggplant in an even layer on two or more rimmed baking sheets. Brush both sides of the slices with olive oil, then season with oregano, salt, and pepper. Bake for 15 minutes, then flip and bake until lightly browned, about 10 minutes more. Set the eggplant aside, and reduce the oven temperature to 400°F.
Meanwhile, bring a large pot of salted water to a boil. Cook the lasagna sheets for 4 minutes. They should still be fairly firm. Drain and rinse under cold water to stop the cooking process. Transfer the cooked sheets to a parchment-lined baking sheet in even layers, separated by parchment.
In a medium bowl, add the ricotta cheese, 3 ounces of mozzarella cheese, 1 ½ ounces of Parmesan cheese, and the chopped basil. Mix until well combined and season to taste with salt and pepper.
Spread ¾ cup of tomato sauce in an even layer at the bottom of a 9 x 13 baking dish. Top with ¼ of the cooked lasagna sheets, arranged in an even layer.
Evenly distribute ⅓ of the roasted eggplant over the lasagna sheets, followed by ⅓ of the cheese mixture. Repeat this layering process two more times with the remaining tomato sauce, lasagna sheets, eggplant, and cheese mixture.
Finish with the remaining ¾ cup of tomato sauce and the last layer of lasagna sheets. Top evenly with the remaining 4 ounces of mozzarella cheese and 1 ½ ounces of Parmesan cheese.
Cover the dish with foil and bake for 40 minutes. Remove the foil and continue to bake until the cheese is melty and golden on top, about 15 minutes more. Let the lasagna cool for 10 minutes before serving.
