layered: 1 c sauce, 3 noodles, 1/3 of cheese mixture, 1 c mozzarella, 1/3 of spinach-mushroom mixture, 1 c sauce. repeat layers. last layer add just a little tomatoe sauce and mozzarella. bake covered in foil for 50 minutes, last 10 minutes add 1/3 c parmesean and bake uncovered last 5-10 minutes.