Slice the eggplants into 1/2 inch thick rounds. Sprinkle them lightly with salt and let them sit for about 20 minutes to draw out excess moisture and bitterness. Pat them dry with a paper towel.

Preheat your oven to 375°F (190°C). Lay the eggplant slices on a baking sheet in a single layer. Drizzle with olive oil and roast for 25-30 minutes or until tender and slightly golden.

Mix the ricotta cheese with grated Parmesan, Italian seasoning, salt, and pepper in a bowl until well combined.

In a 9x13-inch baking dish, start with a layer of marinara sauce to cover the bottom. Add a layer of roasted eggplant slices, followed by dollops of the ricotta mixture. Repeat the layers and finish with a layer of marinara sauce on the top.

Sprinkle the shredded mozzarella cheese evenly on top. Cover the casserole with aluminum foil and bake for about 25 minutes. Remove the foil and bake for another 15-20 minutes, until the cheese is bubbling and golden.

Let the casserole cool for a few minutes before garnishing with fresh basil. Cut into squares and serve.