Arrange the eggplant slices on a paper towel-lined baking sheet and sprinkle them generously with salt, then cover with another paper towel; leave them to sit for 45 minutes to draw out excess moisture. After resting, pat the eggplant dry with fresh paper towels to remove moisture and salt.
Warm your oven to 400°F and lightly coat a large sheet pan with grease. In one bowl, stir together the panko breadcrumbs, parmesan cheese, olive oil, and Italian seasoning. In another bowl, whisk the eggs with the water. Place the flour in a third bowl.
Dredge each eggplant slice first in the flour, then dip in the egg wash, and finally press firmly into the breadcrumb mixture to coat thoroughly. Lay each coated slice on the prepared sheet pan and repeat until all slices are coated. Bake the eggplant for about 30 to 35 minutes until the coating is golden and crisp.
Pour roughly 1 cup of marinara sauce into the base of a 9x13-inch baking dish. Layer half of the baked eggplant over the sauce, then spread another cup of marinara and sprinkle with ¾ cup of mozzarella. Add the remaining eggplant atop the cheese layer, then top with the remaining marinara and mozzarella.
Reduce the oven temperature to 375°F, cover the baking dish with aluminum foil, and bake for 25 minutes. Remove the foil and bake uncovered for an additional 20 minutes until the cheese is bubbly and begins to brown lightly.
Let the dish cool for about 5 minutes before slicing. Garnish with fresh chopped basil before serving for added flavor and color.