Vegan Baked Mostaccioli

Here is my favorite vegan baked mostaccioli recipe, with hearty pasta, vegan sausage, marinara sauce, peppers and onions, and plenty of melted vegan mozzarella on top.

This baked mostaccioli is a regular weeknight dinner at our house. I love that it’s filling, easy to throw together, and the leftovers taste even better the next day. Plus, it makes enough to feed the whole family with seconds!

What Kind of Vegan Sausage Should I Use?

There are tons of vegan sausage options at the grocery store these days, and honestly, most of them will work great in this baked mostaccioli. You can go with Italian-style vegan sausage for a classic flavor, or spicy if you want a little kick. Brands like Beyond Meat, Field Roast, and Tofurky all make solid options that crumble nicely and hold up well in baked dishes. If you can’t find vegan sausage or want to skip it altogether, you could substitute with crumbled tempeh or even extra veggies like mushrooms and zucchini for a heartier texture.

Options for Substitutions

This baked pasta is pretty forgiving when it comes to swaps:

• Mostaccioli: Don’t stress if you can’t find mostaccioli – penne, rigatoni, or ziti work just as well since they’re all similar tube-shaped pastas that hold sauce nicely.
• Vegan sausage: You can swap this with crumbled firm tofu, tempeh, or even lentils for a whole food option. If using tofu or tempeh, crumble it and season with Italian herbs, fennel seeds, and a pinch of red pepper flakes to mimic that sausage flavor.
• Green pepper: Red, yellow, or orange bell peppers work great here. You could also use mushrooms, zucchini, or eggplant if you want to switch up the veggies.
• Vegan mozzarella: If you can’t find vegan mozzarella, try using cashew cream or a homemade cashew cheese sauce on top. Just blend soaked cashews with nutritional yeast, garlic powder, and a bit of lemon juice.
• Marinara sauce: Any tomato-based pasta sauce works here – arrabbiata for more spice, or plain crushed tomatoes seasoned with Italian herbs if you want to keep it simple.

Watch Out for These Mistakes While Baking

The biggest mistake when making baked mostaccioli is overcooking the pasta during the initial boil, which leads to mushy noodles after baking – aim to undercook them by about 2 minutes since they’ll continue cooking in the oven.

Another common error is skipping the step of breaking up the vegan sausage into small crumbles while cooking, as large chunks won’t distribute evenly throughout the dish and can make serving awkward.

To prevent a dry casserole, make sure your marinara sauce is on the thinner side (add a splash of pasta water if needed), and don’t forget to keep that foil on for the first 15 minutes to trap moisture before letting the cheese brown.

For extra flavor, season your pasta water generously with salt and taste your sauce before mixing everything together, since vegan cheeses often have less salt than dairy versions.

What to Serve With Baked Mostaccioli?

A big Caesar salad with crunchy romaine and garlic croutons is my go-to side for baked mostaccioli – it adds a nice fresh contrast to the rich, cheesy pasta. Garlic bread is another obvious winner here, especially if you brush it with olive oil and sprinkle some Italian seasoning on top before toasting. I also love serving this with roasted vegetables like zucchini, broccoli, or Brussels sprouts tossed in olive oil and garlic, which helps round out the meal. If you want to keep things simple, even just a side of steamed green beans with a squeeze of lemon works perfectly.

Storage Instructions

Store: Leftover baked mostaccioli keeps really well in the fridge for up to 4 days in an airtight container. I actually think it tastes even better the next day once all the flavors have had time to hang out together. It’s perfect for easy lunches throughout the week.

Freeze: This pasta bake is great for freezing! You can freeze the whole thing or portion it out into individual servings for quick meals later. Just wrap it tightly in foil or use freezer-safe containers, and it’ll stay good for up to 3 months.

Reheat: Warm it up in the oven at 350°F covered with foil until heated through, about 20 minutes. You can also microwave individual portions for 2-3 minutes, stirring halfway through. If it seems a bit dry, just add a splash of marinara or water before reheating.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 2100-2300
• Protein: 65-80 g
• Fat: 50-65 g
• Carbohydrates: 370-400 g

Ingredients

For the main dish:

• 1 lb mostaccioli
• 1.5 tbsp olive oil
• 1 onion (diced into 1/2-inch pieces)
• 1 green pepper (seeded and diced into 1/2-inch pieces)
• 4 cloves garlic (minced)
• 1 pinch red pepper flakes
• 1 pkg vegan sausage
• 5 cups marinara
• salt
• pepper

For the topping:

• 1 pkg vegan mozzarella

Step 1: Prepare Mise en Place and Preheat Oven

• 1 onion
• 1 green pepper
• 4 cloves garlic
• 1 pkg vegan sausage

Preheat your oven to 350°F.

While it heats, dice the onion and green pepper into 1/2-inch pieces, mince the garlic, and crumble or slice the vegan sausage into bite-sized pieces.

Having everything prepped and ready will make the cooking process smooth and prevent anything from burning while you’re chopping.

Step 2: Cook the Pasta

• 1 lb mostaccioli
• salt

Bring a large pot of salted water to a boil and cook the mostaccioli according to package directions until just al dente (don’t overcook—it will continue cooking in the oven).

Drain the pasta and set aside.

I prefer to reserve about 1/2 cup of pasta water just in case the final dish seems too dry, but it’s optional.

Step 3: Sauté the Aromatics and Build Flavor

• 1.5 tbsp olive oil
• 1 onion
• 1 green pepper
• 4 cloves garlic
• 1 pinch red pepper flakes

In a large skillet or Dutch oven, heat the olive oil over medium heat.

Add the diced onion and green pepper, cooking for 6-8 minutes until softened and just starting to caramelize at the edges.

Stir in the minced garlic and red pepper flakes, cooking for 1 minute until fragrant.

This layering of aromatics builds a deeper, more complex flavor foundation for the dish.

Step 4: Cook the Vegan Sausage

• 1 pkg vegan sausage

Add the crumbled vegan sausage to the pan with the sautéed vegetables and cook for 5 minutes, stirring occasionally to break it up and allow it to brown slightly.

This develops more flavor and texture compared to adding it raw to the sauce.

Step 5: Combine and Season the Pasta Mixture

• cooked mostaccioli from Step 2
• sausage and vegetable mixture from Steps 3-4
• 5 cups marinara
• salt
• pepper

Add the cooked mostaccioli from Step 2 to the pan with the sausage mixture, then pour in the marinara sauce and stir everything together until well combined.

Season generously with salt and pepper to taste.

I find that this dish needs a bit more seasoning than you might expect since the pasta tends to absorb flavors—taste as you go and adjust before baking.

Step 6: Assemble and Bake

• combined pasta mixture from Step 5
• 1 pkg vegan mozzarella

Transfer the pasta mixture to a 9×13 inch baking dish, spreading it evenly.

Top with the vegan mozzarella cheese, distributing it so the whole dish gets covered.

Cover the dish tightly with foil and bake for 15 minutes, then remove the foil and bake uncovered for another 15 minutes until the cheese is melted and the edges are bubbling.

The foil traps steam initially to keep everything moist, while removing it at the end allows any excess moisture to evaporate and the cheese to set.

Step 7: Rest and Serve

Remove the baking dish from the oven and let it rest for 3-5 minutes before serving.

This brief rest allows the dish to set slightly and makes serving much easier.

Vegan Baked Mostaccioli

Delicious Vegan Baked Mostaccioli recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 45 minutes mins

Total Time 1 hour hr 7 minutes mins

Servings 6 servings

Calories 2200 kcal

Ingredients

  

For the main dish::

• 1 lb mostaccioli
• 1.5 tbsp olive oil
• 1 onion (diced into 1/2-inch pieces)
• 1 green pepper (seeded and diced into 1/2-inch pieces)
• 4 cloves garlic (minced)
• 1 pinch red pepper flakes
• 1 pkg vegan sausage
• 5 cups marinara
• salt
• pepper

For the topping::

• 1 pkg vegan mozzarella

Instructions

 

• Preheat your oven to 350°F. While it heats, dice the onion and green pepper into 1/2-inch pieces, mince the garlic, and crumble or slice the vegan sausage into bite-sized pieces. Having everything prepped and ready will make the cooking process smooth and prevent anything from burning while you're chopping.
• Bring a large pot of salted water to a boil and cook the mostaccioli according to package directions until just al dente (don't overcook—it will continue cooking in the oven). Drain the pasta and set aside. I prefer to reserve about 1/2 cup of pasta water just in case the final dish seems too dry, but it's optional.
• In a large skillet or Dutch oven, heat the olive oil over medium heat. Add the diced onion and green pepper, cooking for 6-8 minutes until softened and just starting to caramelize at the edges. Stir in the minced garlic and red pepper flakes, cooking for 1 minute until fragrant. This layering of aromatics builds a deeper, more complex flavor foundation for the dish.
• Add the crumbled vegan sausage to the pan with the sautéed vegetables and cook for 5 minutes, stirring occasionally to break it up and allow it to brown slightly. This develops more flavor and texture compared to adding it raw to the sauce.
• Add the cooked mostaccioli from Step 2 to the pan with the sausage mixture, then pour in the marinara sauce and stir everything together until well combined. Season generously with salt and pepper to taste. I find that this dish needs a bit more seasoning than you might expect since the pasta tends to absorb flavors—taste as you go and adjust before baking.
• Transfer the pasta mixture to a 9x13 inch baking dish, spreading it evenly. Top with the vegan mozzarella cheese, distributing it so the whole dish gets covered. Cover the dish tightly with foil and bake for 15 minutes, then remove the foil and bake uncovered for another 15 minutes until the cheese is melted and the edges are bubbling. The foil traps steam initially to keep everything moist, while removing it at the end allows any excess moisture to evaporate and the cheese to set.
• Remove the baking dish from the oven and let it rest for 3-5 minutes before serving. This brief rest allows the dish to set slightly and makes serving much easier.