Baked ziti with spinach

We're going on a mini-vacation soon (visiting family, and the Big Easy), and so you know what that means. Time to clean out the fridge. I won't be buying any groceries between now and the time we get back.

First up: baked ziti. Uses up a box of pasta, a tub of homemade spaghetti sauce, some cheese, and a box of frozen spinach.

1 box ziti, cooked until softened but still too hard to eat
4-5 cups spaghetti sauce
1 lb grated mozzarella
handful grated parmesan
1 box frozen spinach, thawed

Mix the cooked and drained ziti with the spinach, sauce, and half the mozzarella. Pour into an 8x13 casserole dish. Top with the rest of the cheese. Bake at 400 for 25-35 minutes, or until browned and bubbly on top.