For best results, cut the peppers and onions into large (3-4"), evenly-sized pieces before roasting. This helps everything cook evenly and prevent burning! Cutting your 1/2 onion in half again is usually sufficient - for an especially large onion, you may want to cut it once more. Don't worry about breaking every onion layer apart - just throw the onion onto the sheet pan as is and let it break apart naturally when you toss the veggies with the oil! If you notice your veggies (especially the onion) beginning to burn on the edges, use tongs to give everything a toss and redistribute some moisture.

What size baking dish should I use? We used a 10" round casserole dish in these photos, but this recipe also works with a rectangular 8"x10" baking dish.

Additions and substitutions. Use chicken stock in place of veggie stock. Use another short pasta (rigatoni, shells, penne, cavatappi) instead of ziti if you like. Add chopped kale, spinach, mushrooms, additional bell peppers, or caramelized onions. For extra protein, add cooked Italian sausage, beef, or chicken. Stir additions in with the sauce and pasta or use them as a separate layer while assembling the ziti. Use parmesan, fresh mozzarella, havarti, asiago, or gruyere in place of some or all of the cheese. Use goat cheese or cream cheese in place of the ricotta if you prefer. See the post above for more substitution ideas!

This is a fairly light sauce, and a lot of it will soak into the ziti as it cooks, so you'll be left with just a light layer. If you typically find baked ziti to be too dry (or if you just prefer more sauce!) you can double the sauce recipe here or stir in some extra veggie stock, heavy cream, or cauliflower cream to stretch the sauce for a creamier final product. For an ultra-creamy baked ziti, you can also whip up a béchamel sauce and layer it into the casserole along with the cheese.

To make this ziti ahead of time, roast the veggies and cook the pasta as directed. Add an extra 1/3 cup of veggie stock to the sauce (since the ziti will absorb the sauce as it sits). Let everything cool completely, then assemble as instructed, cover with an airtight lid or plastic wrap, and store in the fridge (3-4 days) or freezer (1-2 months) until you're ready for it. For additional make-ahead tips and baking instructions, be sure to read the post above!

This recipe was originally published in 2015. It was updated in 2020 with additional photos, notes, and a more streamlined recipe.