Italian Sausage Baked Mostaccioli with Spinach

Finding a comforting weeknight dinner that the whole family will actually eat can feel impossible sometimes. Between picky eaters, busy schedules, and the temptation to just order takeout, getting a homemade meal on the table is easier said than done.

That’s where this baked mostaccioli with spinach comes in handy. It’s the kind of dish that combines all the cozy goodness of Italian comfort food with enough hidden vegetables to make you feel good about serving it. Plus, it’s a one-dish wonder that you can prep ahead, which means less time in the kitchen and more time doing literally anything else.

What Kind of Italian Sausage Should I Use?

You can use either sweet or hot Italian sausage for this baked mostaccioli, depending on your heat preference. Sweet Italian sausage gives you a milder, more family-friendly flavor, while hot sausage adds a nice kick that pairs well with the red pepper flakes. If you want something in between, try mixing half sweet and half hot sausage for a balanced flavor. Most recipes call for bulk Italian sausage (the kind without casings), but if you can only find links, just remove the casings before cooking – it’s easy to do with a sharp knife.

Options for Substitutions

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

• Italian sausage: Ground beef, ground turkey, or ground chicken work great here. You can also go meatless and add extra veggies like mushrooms or zucchini for a vegetarian version.
• Mostaccioli pasta: Penne, rigatoni, or ziti are perfect substitutes since they’re all tube-shaped pastas that hold sauce well. Just cook according to the package directions.
• Spinach: Fresh or frozen spinach both work fine. If using frozen, make sure to thaw and squeeze out the excess water first. You can also swap in kale or Swiss chard if that’s what you have.
• Ricotta cheese: Cottage cheese is a solid replacement – just blend it smooth if you prefer a creamier texture. Small curd cottage cheese works best.
• Marinara sauce: Any tomato-based pasta sauce will do the job here. You can use store-bought or homemade – whatever you prefer.
• Mozzarella cheese: While mozzarella gives that classic stretchy cheese pull, you can use provolone or a Italian cheese blend if needed.

Watch Out for These Mistakes While Baking

The biggest mistake when making baked mostaccioli is overcooking the pasta during the initial boil – since it continues cooking in the oven, you want to undercook it by about 2 minutes so it stays firm and doesn’t turn mushy. Another common issue is not draining the sausage properly after browning, which can make your casserole greasy, so be sure to tilt the pan and spoon off excess fat before adding the other ingredients. To prevent a dry casserole, make sure your marinara sauce is on the thinner side and reserve a little extra to add if the mixture looks too thick before baking. Finally, let the dish rest for at least 10 minutes after removing it from the oven – this allows the cheese to set and makes it much easier to serve clean portions instead of a sloppy mess.

What to Serve With Baked Mostaccioli?

This hearty baked pasta is pretty filling on its own, but I love serving it with a simple side salad and some garlic bread for a complete Italian-style dinner. A Caesar salad or mixed greens with Italian dressing works great to balance out the richness of all that cheese and sausage. If you want to keep things easy, just warm up some crusty bread and brush it with garlic butter – it’s perfect for scooping up any extra sauce from your plate. For a lighter option, roasted vegetables like zucchini, bell peppers, or broccoli make a nice side that won’t leave you feeling too stuffed.

Storage Instructions

Store: Leftover baked mostaccioli keeps really well in the fridge for up to 4 days. Just cover it tightly with foil or transfer it to an airtight container once it’s cooled down. The flavors actually get even better the next day after everything has had time to meld together!

Freeze: This is one of those dishes that’s perfect for freezing. You can freeze the whole casserole before or after baking for up to 3 months. I like to portion it out into individual servings in freezer-safe containers so I can grab just what I need for a quick dinner.

Reheat: To warm it up, cover with foil and bake at 350°F for about 20-25 minutes if refrigerated, or 45-50 minutes if frozen. You can also microwave individual portions for 2-3 minutes, stirring halfway through to heat evenly.

Estimated Nutrition

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

• Calories: 3400-3700
• Protein: 160-185 g
• Fat: 185-210 g
• Carbohydrates: 225-250 g

Ingredients

For the meat and sauce:

• 1 lb italian sausage (I use Johnsonville mild links with casings removed)
• 1 large onion (diced into 1/2-inch pieces)
• 5 cloves garlic (minced)
• 1 tsp salt
• 1.5 tsp italian seasoning
• 3.5 cups marinara (I prefer Rao’s Homemade for a rich, authentic flavor)
• 2.5 cups spinach (roughly chopped)
• 1/4 tsp red pepper flakes

For the pasta and cheese mixture:

• 14.5 oz mostaccioli pasta (boiled 2 minutes less than package directions for al dente)
• 3.5 cups mozzarella (freshly shredded for better melting)
• 2 cups ricotta
• 1/2 cup parmesan (I like Sargento shredded parmesan for this)
• 1 large egg
• Pinch of nutmeg

Step 1: Prepare Mise en Place and Start the Sauce

• 1 large onion
• 5 cloves garlic
• 2.5 cups spinach

Dice the onion into 1/2-inch pieces, mince the garlic, and roughly chop the spinach.

While you’re prepping, preheat your oven to 425°F and grease a 9×13 inch baking dish.

This prep work ensures everything is ready when you need it, so the cooking flows smoothly without interruption.

Step 2: Build the Meat and Sauce Base

• 1 lb italian sausage
• 1 large onion
• 5 cloves garlic
• 1 tsp salt
• 1.5 tsp italian seasoning
• 3.5 cups marinara

In a large skillet over medium-high heat, brown the Italian sausage (with casings removed) and diced onion together, breaking the sausage into small pieces as it cooks, until the meat is no longer pink and onion is softened, about 8-10 minutes.

Add the minced garlic, salt, and Italian seasoning, then cook for 1 minute until fragrant.

Pour in the marinara sauce and simmer for 5-10 minutes to allow the flavors to meld.

I find that simmering the sauce with the sausage for a few minutes really lets the spices penetrate the sauce rather than having them taste one-dimensional.

Step 3: Finish the Sauce with Spinach and Pasta

• 14.5 oz mostaccioli pasta
• 2.5 cups spinach
• 1/4 tsp red pepper flakes
• sauce mixture from Step 2

While the sauce simmers, bring a large pot of salted water to a boil and cook the mostaccioli pasta 2 minutes less than the package directions to keep it al dente—it will continue cooking in the oven.

Drain the pasta and set aside.

Stir the chopped spinach and red pepper flakes into the sauce from Step 2, cooking until the spinach is wilted, about 2-3 minutes.

The residual heat will soften the spinach without turning it dark and bitter.

Step 4: Prepare the Cheese Filling

• 2 cups mozzarella
• 2 cups ricotta
• 1/4 cup parmesan
• 1 large egg
• Pinch of nutmeg

In a medium bowl, combine the ricotta, 2 cups of freshly shredded mozzarella, 1/4 cup Parmesan, and the egg.

Mix until evenly combined.

I prefer using freshly shredded mozzarella over pre-shredded because it melts much more smoothly and creates a creamier, more cohesive cheese layer without any graininess.

Step 5: Assemble the Baked Mostaccioli

• cooked pasta from Step 3
• sauce mixture from Step 3
• cheese filling from Step 4
• 2 cups mozzarella
• 1/4 cup parmesan

Spread 1/2 cup of the meat sauce from Step 3 on the bottom of your prepared 9×13 inch baking dish.

Layer half of the cooked pasta over the sauce, then spread half of the cheese mixture from Step 4 over the pasta.

Add half of the remaining sauce (about 1.5 cups) on top.

Layer the rest of the pasta, then the remaining cheese mixture, and finish with the final layer of sauce.

Top the whole dish with the remaining 2 cups mozzarella and 1/4 cup Parmesan.

Step 6: Bake and Rest

Bake the assembled mostaccioli in your preheated 425°F oven for 15-20 minutes, until the top is bubbly and the cheese is golden brown.

Remove from the oven and let it rest for 5 minutes before serving—this allows the layers to set slightly so each spoonful holds together nicely instead of sliding around on the plate.

Italian Sausage Baked Mostaccioli with Spinach

Delicious Italian Sausage Baked Mostaccioli with Spinach recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 52 minutes mins

Servings: 8 servings

Calories: 3550

Ingredients Method

Ingredients

  

For the meat and sauce::

• 1 lb italian sausage (I use Johnsonville mild links with casings removed)
• 1 large onion (diced into 1/2-inch pieces)
• 5 cloves garlic (minced)
• 1 tsp salt
• 1.5 tsp italian seasoning
• 3.5 cups marinara (I prefer Rao’s Homemade for a rich, authentic flavor)
• 2.5 cups spinach (roughly chopped)
• 1/4 tsp red pepper flakes

For the pasta and cheese mixture::

• 14.5 oz mostaccioli pasta (boiled 2 minutes less than package directions for al dente)
• 3.5 cups mozzarella (freshly shredded for better melting)
• 2 cups ricotta
• 1/2 cup parmesan (I like Sargento shredded parmesan for this)
• 1 large egg
• Pinch of nutmeg

Method

 

1. Dice the onion into 1/2-inch pieces, mince the garlic, and roughly chop the spinach. While you're prepping, preheat your oven to 425°F and grease a 9x13 inch baking dish. This prep work ensures everything is ready when you need it, so the cooking flows smoothly without interruption.
2. In a large skillet over medium-high heat, brown the Italian sausage (with casings removed) and diced onion together, breaking the sausage into small pieces as it cooks, until the meat is no longer pink and onion is softened, about 8-10 minutes. Add the minced garlic, salt, and Italian seasoning, then cook for 1 minute until fragrant. Pour in the marinara sauce and simmer for 5-10 minutes to allow the flavors to meld. I find that simmering the sauce with the sausage for a few minutes really lets the spices penetrate the sauce rather than having them taste one-dimensional.
3. While the sauce simmers, bring a large pot of salted water to a boil and cook the mostaccioli pasta 2 minutes less than the package directions to keep it al dente—it will continue cooking in the oven. Drain the pasta and set aside. Stir the chopped spinach and red pepper flakes into the sauce from Step 2, cooking until the spinach is wilted, about 2-3 minutes. The residual heat will soften the spinach without turning it dark and bitter.
4. In a medium bowl, combine the ricotta, 2 cups of freshly shredded mozzarella, 1/4 cup Parmesan, and the egg. Mix until evenly combined. I prefer using freshly shredded mozzarella over pre-shredded because it melts much more smoothly and creates a creamier, more cohesive cheese layer without any graininess.
5. Spread 1/2 cup of the meat sauce from Step 3 on the bottom of your prepared 9x13 inch baking dish. Layer half of the cooked pasta over the sauce, then spread half of the cheese mixture from Step 4 over the pasta. Add half of the remaining sauce (about 1.5 cups) on top. Layer the rest of the pasta, then the remaining cheese mixture, and finish with the final layer of sauce. Top the whole dish with the remaining 2 cups mozzarella and 1/4 cup Parmesan.
6. Bake the assembled mostaccioli in your preheated 425°F oven for 15-20 minutes, until the top is bubbly and the cheese is golden brown. Remove from the oven and let it rest for 5 minutes before serving—this allows the layers to set slightly so each spoonful holds together nicely instead of sliding around on the plate.