Lasagna With Spinach and Roasted Zucchini

extra virgin olive oil

medium zucchini, cut in half crosswise, then cut lengthwise into 1/4-inch-thick slices

Salt and freshly ground black pepper

bunch spinach, washed and stemmed, or 1/2 pound bagged baby spinach

marinara sauce, preferably homemade from fresh or canned tomatoes

ricotta cheese

egg

water

cinnamon

to 8 ounces no-boil lasagna

freshly grated Parmesan