Zucchini Noodle Casserole

Want to shake up your typical dinner casserole? Bake spiralized zucchini noodles with sausage and tomato sauce, then top it with three different cheeses. This zucchini noodle casserole recipe is low-carb and gluten-free!

Zucchini Noodle Casserole on a Fork with More in a Plate

Simply Recipes / Michelle Becker

You know what my favorite kitchen gadget is this summer?

A spiralizer, or a spiral vegetable slicer. It's basically a lathe that lets you turn a cylindrical vegetable such as zucchini or sweet potato into "noodles", or in the case of zucchini, "zoodles".

I love pasta as much as anyone, but the truth is my body will not cooperate and let me eat as much pasta as I want without undesired consequences.

So, the idea of making noodles with zucchini? Tempting, but could it possibly be as good as pasta?

Ladies and gentlemen, I hereby announce that zucchini noodles, at least cooked the way I've prepared them in this casserole, are shockingly good.

This cheesy baked zucchini noodle casserole is like baked spaghetti, but with zucchini noodles instead of spaghetti. The flavor of zucchini is terrific with the tomato, onion, garlic, sausage, and cheeses.

You can even twirl the "zoodles" on your fork! The noodle shape almost tricks your mouth into thinking you are eating spaghetti. But you aren't. This is gluten-free, low carb, and completely satisfying.

In this version, we are adding sweet Italian sausage to the tomato sauce, but you could easily make it vegetarian by using cubed eggplant or sliced mushrooms instead of the sausage.

Zucchini Noodle Casserole in a Casserole Dish with Some on a Spatula

Simply Recipes / Michelle Becker

The Secret to Mush-Free Zucchini Noodles

The main complaint that people have when cooking with zucchini noodles is that they end up mushy. My approach to how to deal with this is to salt the zucchini noodles well and let them drain of their excess moisture. You can easily get 1/2 cup of zucchini water out of the zucchini just from letting them sit over a colander or sieve.

So, this is my new favorite way to cook with zucchini noodles. Have you experimented with them? Please let me know in the comments what has worked or not worked for you.

How to Make This Casserole Vegetarian

We are using Italian sausage in the sauce. If you would like to make the sauce vegetarian, you can use either eggplant or mushrooms (or both). If you use eggplant, cube the eggplant into 3/4-inch cubes, salt it, and let it drain like the zucchini. Then brown it in a tablespoon or two of olive oil in place of the sausage.

If using mushrooms, slice them into 1/4-inch slices and dry sauté them (no added fat, just put the mushrooms into the hot pan) until they have released most of their moisture, then add them to the tomato sauce.

Zucchini Noodle Casserole in a Casserole Dish

Simply Recipes / Michelle Becker

How to Avoid a Watery Casserole

To help the zucchini release some of their moisture, we salt and drain the noodles first. This quick process is enough to prevent a watery mixture for most grocery store zucchini, but the water content in each vegetable can vary.

If you are using garden zucchini or especially large zucchini, they likely contain excess water. Salt and let them drain for 1-2 hours. Before adding to the sauce, you can give the noodles a gentle press in the colander with the back of a wooden spoon to squeeze out a bit more liquid.

Using Frozen Zucchini Noodles

Fresh zoodles work best for this recipe, but frozen also works well. Defrost completely in the fridge, drain, then salt and drain again per the recipe instructions before using.

Recipes for Zucchini Noodles and More!

From the Editors Of Simply Recipes

Zucchini Noodle Casserole

Prep Time 20 mins
Cook Time 50 mins
Total Time 70 mins
Servings 6 servings

The amount of water content in zucchini can vary greatly depending on their size and age. If you’re using large or very fresh zucchini, let the noodles drain after salting for up to 2 hours.


  • 3 pounds zucchini (about 5 to 6 good-sized zucchini, enough for 8 to 10 cups of salted zucchini noodles)

  • 2 teaspoons salt, divided

  • 1 tablespoon extra-virgin olive oil

  • 8 ounces Italian sausage (in bulk, out of casings)

  • 1 1/2 cups diced onion

  • 3 cloves garlic, minced (about 1 tablespoon)

  • 1 (15-ounce) can crushed tomatoes

  • 1/2 cup thinly sliced basil leaves

  • 3/4 cup ricotta cheese

  • 2 cups mozzarella cheese (about 8 ounces)

  • 1/2 cup grated Parmesan cheese

Special Equipment

  • Spiralizer


  1. Preheat the oven and prepare a dish:

    Preheat the oven to 350°F and oil a 9 x 13-inch or 8 x 12-inch casserole dish.

  2. Spiralize the zucchini, toss with salt, and let drain:

    Using a spiralizer, make zucchini noodles (zoodles) following the manufacturer's directions. You should have a generous 8 cups of zucchini noodles.

    Place in a colander over a bowl. Snip the zucchini noodles with scissors here and there to keep them from tangling too much.

    Toss the zoodles with 1 1/2 teaspoons of salt. Let the zoodles drain of excess moisture while you make the sauce.

    Zucchini in a Spiralizer for Noodle Casserole

    Simply Recipes / Michelle Becker

    Bowl of Spiralized Zucchini for Zoodle Recipe

    Simply Recipes / Michelle Becker

  3. Lightly brown the sausage:

    Coat the bottom of a large sauté pan with olive oil. Break up the Italian sausage into small clumps in the pan. Heat on medium heat and gently cook the sausage until it is just cooked through and lightly browned. Remove to a bowl. Discard all but 1 tablespoon of rendered fat.

    Pan of Sausage for Zucchini Noodle Casserole

    Simply Recipes / Michelle Becker

  4. Brown the onions and garlic:

    In the same pan, add the chopped onion. Cook until softened and lightly colored, about 5 to 6 minutes. Add the minced garlic and cook 1 minute more.

    Pan of Onions for Noodle Zucchini Recipe

    Simply Recipes / Michelle Becker

  5. Add the tomatoes and cooked sausage, simmer, then add the basil:

    Add the canned crushed tomatoes and cooked sausage to the pot with the onions. Bring to a simmer and lower the heat to maintain a low simmer. Cook for 5 to 6 additional minutes.

    Stir in the thinly sliced basil and 1/2 teaspoon of kosher salt.

    Pan of Tomato, Sausage, and Onions for Zucchini Noodle Recipe

    Simply Recipes / Michelle Becker

  6. Combine the zoodles and the sauce:

    Add the zucchini noodles to the pot with the tomato sausage sauce. Gently stir to combine so that all of the noodles are coated with sauce.

    Transfer to the prepared casserole dish and spread into an even layer.

    Zucchini Noodle Mixed into Sauce for Casserole Recipe

    Simply Recipes / Michelle Becker

  7. Top with cheese, then bake:

    Arrange the ricotta in clumps on the casserole. Press the ricotta into the zucchini noodles to penetrate the casserole a bit. Mix the grated mozzarella and Parmesan cheese together and sprinkle over the top in an even layer.

    Bake at 350°F, uncovered, for 35 minutes, or until the top is lightly browned and bubbly. Let cool for 10 minutes before serving.

    Store leftover zucchini noodle casserole in an airtight container in the fridge for up to 3 days, or tightly wrap and freeze for up to 1 month.

    Did you love the recipe? Leave us stars below!

    Zucchini Noodle Casserole Topped with Ricotta

    Simply Recipes / Michelle Becker

    Zucchini Noodle Casserole Topped with Cheese

    Simply Recipes / Michelle Becker

    Zucchini Noodle Casserole in a Casserole Dish

    Simply Recipes / Michelle Becker

Nutrition Facts (per serving)
424 Calories
27g Fat
23g Carbs
26g Protein
Show Full Nutrition Label Hide Full Nutrition Label
Nutrition Facts
Servings: 6
Amount per serving
Calories 424
% Daily Value*
Total Fat 27g 34%
Saturated Fat 12g 60%
Cholesterol 68mg 23%
Sodium 1612mg 70%
Total Carbohydrate 23g 8%
Dietary Fiber 5g 16%
Total Sugars 11g
Protein 26g
Vitamin C 40mg 198%
Calcium 436mg 34%
Iron 3mg 16%
Potassium 1109mg 24%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
Nutrition information is calculated using an ingredient database and should be considered an estimate. In cases where multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.