Baked Eggplant Parmesan Mac and Cheese

0 Preheat oven to 450 (230 C) degrees. Bring a large (4-6 quarts) pot of water to a boil and add 3 tablespoons salt.
2 Slice eggplant in half lengthwise, then slice each in half again. Slice crosswise into ½-inch thick pieces.
3 Whisk together egg, 1 teaspoon salt, pepper, garlic and oregano in a large bowl. Add eggplant and toss to coat. Dredge eggplant in the panko crumbs on a cookie sheet.
4 Place a large rimmed baking sheet on the oven rack and heat for 10 minutes — it may warp a bit, but don't worry.
5 Carefully pour enough olive oil over the bottom of the preheated baking sheet to cover to a depth of ¼-inch. Lay eggplant on the pan and roast 12 minutes. Flip eggplant slices over with a spatula, and roast an additional 10 minutes or until eggplant is tender and crust is golden. 
Make the sauce
6 Meanwhile, heat a medium saucepan over moderate heat. Add butter and heat until foaming subsides and butter is melted. Whisk in flour; cook 1 minute. Slowly pour in milk while whisking. Bring to a simmer, then lower heat and cook 5–10 minutes, whisking occasionally, until thickened. Remove from heat and stir in ¼ cup of the Parmesan, ½ teaspoon salt and freshly ground black pepper.
7 Cook pasta according to package directions, until al dente. Drain.
8 Lower oven temperature to 400 (200 C) degrees. Combine the pasta with the cheese sauce and transfer to a large casserole or baking dish. Top with the eggplant (and any crisp crumbs in the pan), marinara, remaining Parmesan and mozzarella cheese. Bake 12-15 minutes, until hot and cheese is melted. Sprinkle with parsley and serve.