Preheat the oven to 425°F. In a small bowl, mix together the oregano, basil, garlic powder, and parsley.Slice the eggplants into ¼-inch thick rounds and arrange them in a single layer on lightly greased baking sheets.Drizzle the eggplant slices with olive oil and sprinkle with salt, pepper, and the seasoning blend. Toss gently to coat evenly.Roast the eggplant in the oven for 20 minutes until tender. Reduce the oven temperature to 375°F after roasting.Meanwhile, combine the panko breadcrumbs and melted butter in a skillet over medium heat. Toast the breadcrumbs until golden brown, about 2–3 minutes.In a 9x13-inch casserole dish, spread a thin layer of marinara sauce. Layer half of the roasted eggplant slices on top, sprinkle half of the toasted panko breadcrumbs, dollop with half the marinara sauce, and sprinkle half of the Parmesan and mozzarella cheese.Repeat the layers with the remaining ingredients. Cover the dish with foil and bake at 375°F for 18 minutes.Remove the foil, sprinkle the top with the remaining toasted breadcrumbs, and bake uncovered for an additional 5 minutes, until bubbly and golden on top.Allow the casserole to cool slightly before slicing and serving.