Combine spaghetti, pasta sauce, and veggies for an easy and sliceable vegetarian baked spaghetti! Inspired by spaghetti pie, this is a fantastic meatless option for family dinners and it's super easy to customize.
This vegetarian baked spaghetti features simple ingredients and it's really easy to make your own. It features sauteed mushrooms, a simple homemade tomato sauce, and an ample amount of shredded mozzarella
I think of baked spaghetti as a sort of casserole, and even though I usually make it in my cast iron skillet it can also be cooked in a 9x13-inch baking dish.
The result is cheesy and sliceable spaghetti dappled with mushrooms, or the veggies of your choosing!
Jump to:
Why this recipe works
- Inspired by spaghetti pie because it is sliceable and cooked in a cast-iron skillet. Spaghetti pie usually uses ricotta-coated noodles as a "crust" topped with sauce. This lighter version uses a delicious yet simple combination of spaghetti and tomato sauce baked in a cast-iron dish.
- Family-friendly: Vegetarian baked spaghetti is great for family dinners because it is simple but satisfying.
- Hidden veggies: This recipe features finely diced mushrooms, but you can blend extra veggies into the sauce or omit the mushrooms.
- Versatile: I love adding meatless grounds or Impossible meat for a "meaty component". Feel free to get creative and add extra veggies to the sauce.
Looking for more like this? If you like this recipe then you'll love my vegetarian one-pot spaghetti and vegetarian pasta bake.
Ingredients and substitutions
- Spaghetti noodles: White, whole wheat, or even protein pasta will work. Cook the noodles until al dente so that the baked spaghetti retains texture.
- Pasta sauce: I personally think that homemade pasta sauce is the best part of spaghetti pie, but using a 24-28 ounce jar of store-bought pasta sauce is an easy way to cut down on cooking time.
- Veggies: Finely diced mushrooms add flavor and nutrition. You can also add finely chopped celery, broccoli, carrots, whatever! Just make sure to saute until most of the water is evaporated out and pour off any excess liquid before adding the tomatoes. Make the veggies “hidden” by blending them into the tomato sauce in a blender.
- Mozzarella: Shredded mozzarella acts as “glue” to hold the spaghetti together and is a necessary addition to most casseroles. Make this dish vegan by using an equal amount of vegan shreds instead.
- Protein: If you'd like to add extra plant-based protein, consider sauteing tempeh or plant-based sausages along with the mushrooms.
Step by step instructions
- Saute the vegetables: Heat a large 12-inch skillet over medium-high heat. Add one tablespoon of olive oil. Once hot, add minced garlic, onions, and finely chopped mushrooms. Sprinkle with ¼ teaspoon salt. Saute 6-8 minutes, or until mushrooms are soft. Drain off excess liquid.
- Make the sauce: Add chopped parsley, rosemary, thyme, and oregano. Saute another 30 seconds to bloom the herbs. Add extra oil as needed. Add the crushed tomatoes with juices, sugar, and black pepper. Simmer for about 15 minutes to allow the flavors to develop. At this point, you can blend the sauce in a blender or move to the next step.
- Assemble the spaghetti bake: Mix together half of the shredded mozzarella, all of the cooked spaghetti, and all of the pasta sauce. Place in a 12-inch cast-iron skillet or baking dish.
- Bake until golden: Sprinkle with remaining shredded mozzarella. Bake at 350F until the cheese is melted and golden, about 20 minutes.
Tips and variations
- Baking dish: I use a 12-inch cast iron skillet but you can use a regular casserole dish if you don’t have an oven-proof skillet. Any 9x13-inch or similarly sized baking dish will do.
- Moisture: The less watery your veggies are, the better the baked spaghetti holds together. Make sure to salt the mushrooms and onions when you add them to the skillet to draw out extra moisture. Drain off extra moisture before adding tomatoes.
- Coat the spaghetti: Cover the spaghetti with the sauce and cheese as much as you can to keep it from drying out in the oven. Though admittedly the crispy spaghetti bits are the best part!
- Add protein: Saute meatless crumbles or Impossible sausage alongside the mushrooms to increase the protein, or add a drained can of chickpeas.
- Serving ideas: I like to add a green salad like arugula salad or kale chickpea salad for extra fiber. Serve with a cheddar biscuit on the side for the best kind of comfort food meal.
Storage tips
- Leftovers: Keep leftover baked spaghetti refrigerated in a closed container for 3-4 days.
- Reheating: Reheat individual servings in the microwave or reheat the entire casserole in the oven. To do this, cover with foil and bake at 325F until warmed through, about 15-20 minutes.
- Freezing: Baked spaghetti is great as a freezer meal. It will last in the freezer for up to 3 months. Let the casserole cool to room temp before covering with foil and freezing. You can also slice the casserole and freeze it in individual portions. I like to do this for an easy "freezer dinner".
- Make-ahead: The pasta sauce can be made up to 48 hours in advance and stored in the fridge. I don't recommend assembling the actual spaghetti casserole in advance because the spaghetti will absorb the sauce and soften as it refrigerates.
More favorite pasta recipes
If you like this recipe you'll love this vegetarian chili mac.
Did you try this recipe? You can leave a star rating in the recipe card or a review in the comments below. Or check out my new cookbook and keep up to date with my YouTube, Instagram, TikTok, or newsletter!
📖 Recipe
Vegetarian Baked Spaghetti
Ingredients
- 1 tablespoon extra virgin olive oil more as needed
- 1 small yellow onion finely chopped
- 8 ounces baby bella mushrooms finely chopped
- 3 cloves garlic minced
- ½ teaspoon kosher salt
- ¼ cup fresh chopped parsley
- 1 tablespoon each fresh chopped rosemary, thyme, oregano see note #1
- 28 ounces crushed tomatoes
- ½ teaspoon granulated sugar
- ¼ teaspoon black pepper
- 12 ounces whole wheat spaghetti regular spaghetti also works
- 1 ½ cups shredded mozzarella cheese divided
Instructions
- Preheat the oven to 350F. Lightly butter or oil a 12-inch cast iron skillet or 9x13-inch casserole dish, depending on which you prefer using.
- Heat a large skillet over medium-high heat. Add one tablespoon of olive oil. Once hot, add the mushrooms, onions, garlic, and salt. Add additional veggies now if desired. Saute for 6 to 8 minutes, or until mushrooms are softened. Drain off any excess liquid.
- Add chopped parsley, rosemary, thyme, and oregano. Saute another 30 seconds to bloom the herbs. Add extra oil as needed.
- Add the crushed tomatoes with juices, sugar, and black pepper. Bring to a rapid simmer over medium-high heat. Reduce to a low simmer over medium-low heat. Simmer for 15 minutes then turn off the heat. Taste for salt.
- Meanwhile, cook the spaghetti to al dente in well salted water, according to package instructions. Once cooked, drain the pasta. Transfer spaghetti to the pasta sauce. Stir in ¾ cup shredded mozzarella.
- Transfer spaghetti and sauce mixture to the oiled cast iron pan or baking dish. Top with remaining ¾ cup of shredded mozzarella.
- Bake at 350F for 20 minutes, or until mozzarella is golden and bubbling. Remove from the oven and let rest 5 minutes before slicing to serve. Enjoy!
Notes
- Fresh herbs: Rosemary, oregano and thyme can each be replaced with 1 teaspoon dry herbs.
- Extra veggies: Add carrots, squash, peas, or other vegetables for additional veggies. Fresh or frozen works, but if using frozen make sure to thaw first and add at the same time as the tomatoes. peas for extra veggies. You can blend the pasta sauce after simmering if you prefer a "hidden veggie" sauce. Make sure to vent the blender as it will be very hot.
- Add protein: Saute meatless crumbles or Impossible sausage alongside the mushrooms to increase the protein, or add a drained can of chickpeas.
- Storage: Keep refrigerated in a closed container for 3 to 4 days. To freeze, cover the cooled casserole with foil and freeze for up to 3 months. Let thaw overnight before reheating, covered, in the oven at 325F until warmed through.
Katerina | Once a Foodie
This is such a great idea, Cassidy, my kids would love this for a weeknight dinner! It would be so fun to serve a wedge of this and I love the idea of boosting the sauce with extra veggies too. Thanks for the inspiration!
Cassidy Reeser, RDN, LD
Thanks, Katerina! I hope you love it!