Preheat the oven to 350°F. Cut the zucchini lengthwise into ¼-inch slices. Place the zucchini in a basket over 1 inch of boiling water. Cover and steam until just tender, five to six minutes. Drain and pat dry. Editor's Tip: Steaming the zucchini first helps eliminate excess moisture when it bakes in the casserole, but don't skip the pat-dry moment! If the zucchini is too damp, you'll end up with a casserole soup instead of a sliceable bake. A few paper towels now will result in firm, cheesy layers later.

In a large bowl, combine the ricotta, egg substitute, 3 tablespoons of bread crumbs, 3 tablespoons of Parmesan, parsley, oregano, basil and pepper. Set it aside.

Spread a third of the spaghetti sauce in a 13x9-inch baking dish coated with cooking spray. Sprinkle with 2 tablespoons bread crumbs. Cover with half each of the zucchini, ricotta mixture and mozzarella. Repeat the layers of sauce, zucchini, ricotta mixture and mozzarella. Cover with the remaining sauce.

Combine the remaining 3 tablespoons of bread crumbs and 2 tablespoons of Parmesan, and sprinkle them over the top.

Cover the casserole and bake it for 45 minutes. Uncover the dish and bake for an additional 15 minutes or until golden brown on top. Let it stand 15 minutes before cutting. Sprinkle with fresh basil if desired. Editor's Tip: Letting the casserole rest isn't just for show—this step helps the layers settle, allowing you to slice it cleanly.