Method:
Preheat oven to 350°F. In a large bowl mix ricotta, 1/2 cup of the mozzarella, 1/2 cup of the 3-cheese blend, egg, spinach, salt, pepper and oregano. In another bowl, combine the remaining 1/2 cup mozzarella and 1/2 cup 3-cheese blend. Set both bowls aside. In a 9- x13-inch non-reactive baking pan, layer 1 cup of the sauce, then a layer of noodles and a layer of the ricotta-spinach mixture; repeat. Top with sauce then sprinkle with remaining cheeses. Pour 1 cup water around the edges of pan, then cover with parchment paper, then very tightly with foil. Bake 1 1/4 hours, then set aside to let stand for 15 minutes before serving.