Using a potato peeler, slice the two sides of each zucchini into thin flat strips, peeling until you reach the center. You will end up with 50-60 slices.
In a small mixing bowl, combine the ricotta, parmesan, egg, spinach, basil, nutmeg, salt and pepper. Separately, fill the bottom of a 9×13 baking dish with the marinara sauce. You can also portion control the ravioli by splitting them up between smaller baking dishes.
To assemble the zucchini ravioli: overlap two strips of squash then overlap two more strips perpendicular on top of the first strips, creating a T shape. Spoon 1 tablespoon of filling in the center of the squash then bring the ends of the strips together, overlapping each other. Turn the ravioli over and place in the baking dish to seal the bottom. Top with olive oil, mozzarella, more parmesan, salt and pepper.
Bake the zucchini ravioli for 30 minutes, until the zucchini is al dente and the cheese on top is turning golden brown. Serve with more marinara sauce, parmesan and fresh basil.