Preheat oven to 350°F. In a large stock pot, bring salted water to a boil over medium-high heat. Add the eggplant and gently simmer until soft, about 12 minutes.
Drain well, place in a large mixing bowl and mash well. Add eggs, milk, 1⁄2 cup bread crumbs, onion, salt, pepper, and mozzarella. Stir until well-blended.
Prepare a 1 1⁄2 quart baking dish with pan spray. Pour in eggplant mixture. Combine remaining 3⁄4 cup bread crumbs with melted butter and Italian seasoning (if using) and sprinkle on top. Bake until the top is golden brown – approximately 30 minutes.