Spaghetti Squash Casserole

Introduction

Did you know a cup of cooked spaghetti squash has only about 8 to 10 grams of net carbs, while a cup of cooked pasta has around 40? According to USDA FoodData Central, spaghetti squash is also low in calories, which is why this spaghetti squash casserole has become a weeknight favorite on keto tables. Many people believe a low-carb dinner can’t feel cozy, filling, or family-friendly. This spaghetti squash casserole recipe proves otherwise. It’s cheesy, creamy, and full of savory flavor, with tender squash strands standing in for noodles.

At My Blog, I’m always looking for comfort food that doesn’t wreck your macros. This dish is one of the easiest ways to get that “baked pasta” feeling with just a handful of ingredients and one baking dish. If you want more ideas like it, browse our keto dinner recipes.

Ingredients List

For the best spaghetti squash casserole, start with fresh, simple ingredients. Here is what you need:

• 1 large spaghetti squash (about 3 pounds): the golden, mild-tasting base that turns into soft, buttery strands
• 1 tablespoon olive oil: for roasting and a lightly caramelized edge
• 1 pound ground Italian sausage: savory, a little spicy, and full of flavor
• 1 cup sugar-free marinara sauce: look for under 5 grams of carbs per half cup
• 4 ounces cream cheese, softened: this gives the casserole its creamy texture
• 1 cup shredded mozzarella: for that gooey, stretchy top
• ½ cup grated Parmesan: salty and nutty
• 2 cloves garlic, minced
• 1 teaspoon Italian seasoning
• Salt and black pepper to taste
• Fresh basil for garnish

Substitutions:

• Swap the sausage for ground beef, turkey, or shredded rotisserie chicken.
• Use mascarpone or heavy cream in place of cream cheese.
• For a vegetarian version, use sautéed mushrooms and spinach instead of meat.
• No Parmesan? Pecorino Romano works well.

Timing

• Prep time: 15 minutes
• Cook time: 60 minutes
• Total time: 75 minutes

This spaghetti squash casserole takes about 75 minutes from start to finish. Most of that is hands-off oven time, so you can prep the rest of your meal while the squash roasts. Compared with many baked pasta casseroles, which often run 90 minutes or more, that’s roughly 15 to 20 percent faster.

Step-by-Step Instructions

Step 1: Preheat and Prep the Squash

Preheat your oven to 400°F (200°C). Carefully cut the spaghetti squash in half lengthwise. A sharp, heavy knife helps, and microwaving the whole squash for 2 minutes first softens the skin and makes cutting safer. Scoop out the seeds.

Step 2: Roast the Squash

Brush the cut sides with olive oil and season with salt and pepper. Place the halves cut-side down on a baking sheet. Roast for 35 to 40 minutes, until a fork pierces the skin easily. Cut-side down helps the squash steam in its own moisture. If you want to master this base step, see our guide to baked spaghetti squash.

Step 3: Shred and Drain

Let the squash cool for 10 minutes. Use a fork to scrape the flesh into long strands. Place the strands in a clean kitchen towel and squeeze out the extra water. This is the secret to a casserole that’s creamy, not soggy.

Step 4: Cook the Sausage

While the squash cools, brown the sausage in a large skillet over medium heat for 6 to 8 minutes. Add the garlic and Italian seasoning during the last minute. Drain any excess grease, then stir in the marinara and cream cheese until smooth and bubbly.

Step 5: Bake the Spaghetti Squash Casserole

Lower the oven to 375°F (190°C). Mix the squash strands into the sausage mixture along with half the mozzarella. Spread everything into a greased 9×13 baking dish. Top with the remaining mozzarella and the Parmesan. Bake for 20 to 25 minutes, until golden and bubbling. Broil for 2 minutes if you like a browned top.

Step 6: Rest and Serve

Let the dish rest for 5 minutes so it sets and slices neatly. Sprinkle with fresh basil and serve warm.

Nutritional Information

Each serving of this spaghetti squash casserole makes a satisfying, balanced keto meal. The values below are estimates for 1 of 6 servings and will vary with your brands.

• Calories: about 320
• Fat: 22 g
• Protein: 20 g
• Total carbs: 10 g
• Fiber: 3 g
• Net carbs: 7 g

Spaghetti squash is also a good source of vitamin C, potassium, and manganese, which most traditional pasta lacks. Check the labels on your marinara and sausage, since added sugar can quietly raise the carb count.

Healthier Alternatives for the Recipe

You can tweak this spaghetti squash casserole to fit different goals and diets:

• Lighter version: use lean ground turkey and part-skim mozzarella to cut calories and saturated fat.
• Extra veggies: fold in chopped spinach, zucchini, or mushrooms for more fiber and nutrients.
• Dairy-free: use cashew cream cheese and dairy-free shredded cheese.
• Higher protein: add shredded chicken or an extra half pound of ground beef.
• Gluten-free: the base recipe is already gluten-free, but check your sausage and marinara labels.

Serving Suggestions

Serve spaghetti squash casserole with a crisp Caesar salad (no croutons) or a simple arugula salad dressed in olive oil and lemon. Steamed broccoli or garlic-roasted green beans add color and crunch. For a cozy Italian night, add keto garlic “bread” made from almond flour. Leftovers also work well as a quick lunch, and you can stuff the mixture back into the squash shells for a fun presentation when guests come over.

Common Mistakes to Avoid

• Skipping the draining step. The most common spaghetti squash casserole problem is a watery result. Squeeze the strands in a towel before mixing.
• Overcooking the squash. Mushy squash loses its noodle-like texture. Roast just until a fork slides in easily.
• Cutting across instead of lengthwise. Cutting the squash lengthwise gives you shorter strands. Cutting it across the middle gives you long, spaghetti-like ones.
• Using high-sugar marinara. Some jarred sauces have 8 to 10 grams of sugar per serving, which can push the dish out of keto range.
• Skipping the resting time. Cutting in right away makes the casserole runny. Five minutes makes a big difference.

Storing Tips for the Recipe

Store leftover spaghetti squash casserole in an airtight container in the refrigerator for up to 4 days, in line with USDA guidance on leftovers and food safety. To freeze, cool it completely, wrap it tightly or portion it into containers, and freeze for up to 3 months. Thaw overnight in the fridge. Reheat spaghetti squash casserole in a 350°F oven for 15 to 20 minutes, or microwave single portions for 2 minutes. To save time, you can roast and shred the squash up to 2 days ahead.

Conclusion

This spaghetti squash casserole recipe delivers creamy, cheesy comfort for roughly 7 grams of net carbs per serving. Roast the squash, drain it well, and bake until bubbly. Try it tonight, then leave a comment below, and subscribe to my blog for more easy keto family dinners.

FAQs

Spaghetti Squash Casserole

Recipe by Leese

0.0 from 0 votes

Course: DinnerCuisine: Italian, American

Servings

6

servings

Prep time

15

minutes

Cooking time

1

hour 

Total time

1

hour 

15

minutes

An easy keto spaghetti squash casserole recipe with Italian sausage, marinara, and melted mozzarella. Only 7g net carbs per serving.

Ingredients

• 1 large spaghetti squash (about 3 pounds)

• 1 tablespoon olive oil

• 1 pound ground Italian sausage

• 1 cup sugar-free marinara sauce

• 4 ounces cream cheese, softened

• 1 cup shredded mozzarella

• 1/2 cup grated Parmesan

• 2 cloves garlic, minced

• 1 teaspoon Italian seasoning

• Salt and black pepper to taste

• Fresh basil for garnish

Directions

• Preheat and prep:
  Preheat the oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise and scoop out the seeds.
• Roast the squash:
  Brush with olive oil, season, and roast cut-side down for 35 to 40 minutes until a fork pierces the skin easily.
• Shred and drain:
  Cool for 10 minutes, scrape into strands with a fork, and squeeze out extra water in a clean towel.
• Cook the sausage:
  Brown the sausage for 6 to 8 minutes, add garlic and Italian seasoning, drain the grease, then stir in marinara and cream cheese.
• Bake:
  Lower the oven to 375°F (190°C). Mix the squash with the sausage mixture and half the mozzarella, spread in a 9×13 dish, top with remaining cheeses, and bake 20 to 25 minutes.
• Rest and serve:
  Rest for 5 minutes, garnish with fresh basil, and serve warm.