Traditionally, there are layers of ricotta chess in the lasagna also. Its a bed of sauce, a layer of noodles, spread with ricotta mixture, layer some sauce, top with shredded mozzarella. Repeat the layers till the pan is full almost to the top.
BTW, you can freeze ricotta cheese and re-use for up to 3 or 4 months, thats what I do.
Oh! I never knew you could freeze it and reuse! Thanks Mamaof3!
Ya I make my lasagna layers similarly, first sauce, then noodles, then sauce, then mozzarella cheese, then noodles, then ricotta cheese, then sauce, then noodles, then sauce again, then last layer of mozarella --so easy and oh so yum!!