Combine spinach, egg, 3/4 mozzarella cheese, ricotta, sausage, and oregano.

Spread 1/2 cup of sauce in bottom of 9x13 pan. Put four uncooked lasagna noodles over sauce and spread half of the cheese mixture over the noodles.

Repeat the layer of sauce, four more noodles, the other half of the cheese mixture, and another 1/2 cup of sauce. Top the remaining uncooked noodles. Sprinkle with Parmesan cheese if wanted.

Pour the rest of the sauce over the noodles. Sprinkle with the remaining mozzarella cheese. Pour water around the sides, cover with foil. Bake for one hour at 350 degrees.