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Whether you’re trying to cut down on pasta or meat, this cheesy pesto spaghetti squash makes it easy! Roasted spaghetti squash is baked with a creamy pesto-infused cheese sauce for a flavorful Meatless Monday dinner.
Ah, spaghetti squash. For years, people have been proclaiming it to be the perfect swap for pasta, but let’s be real: spaghetti squash might look like spaghetti, but there’s no mistaking it for pasta.
Instead, let’s appreciate spaghetti squash for what it is! It’s healthy, it’s pretty delicious when you roast it in the oven, and when you pair it with the right ingredients, you won’t even care that it doesn’t taste exactly like spaghetti. Case in point? This cheesy pesto spaghetti squash.
There are not one, not two, but three different cheeses in this recipe. This alone gives the creamy sauce a lot of flavor, but then we add pesto for a bright, herbaceous note to balance out all that richness. My other secret to tasty spaghetti squash is to roast it in the oven, rather than microwaving or steaming it. We all love to save time, but it’s not worth it with spaghetti squash! The longer time in the oven lets a lot of the excess water in the squash bake off, which keeps it from getting soggy and mushy.
What You’ll Need
Not counting the salt and pepper, you’ll only need six ingredients for this cheesy pesto spaghetti squash!
- Spaghetti squash
- Salt and pepper
- Pesto – Use a store-bought pesto or my Pistachio Pesto.
- Ricotta cheese
- Mozzarella cheese – A shredded Italian blend of cheeses will work, too.
- Parmesan cheese
- Milk – If you want to make this keto, you can use cream instead.
What size spaghetti squash should I use?
Use a small spaghetti squash that weighs about a pound and a half. If your grocery store only has larger squash, I recommend increasing the other ingredients to ensure that your squash boats have maximum flavor and cheesiness!
How to Make Cheesy Pesto Spaghetti Squash
Here’s what you’ll need to do to make easy, cheesy baked spaghetti squash:
Prepare. Preheat your oven to 425ºF and place the spaghetti squash halves on a baking sheet. Sprinkle each half with salt. Place the squash in the oven with the cut side up and bake for 15 minutes, or until sightly soft.
Make the cheese sauce. Combine the pesto and cheeses in a bowl, then add the milk and stir. Season to taste with salt and pepper.
Bake. Fill the spaghetti squash boats with the cheese sauce, then cover them tightly with foil. Return them to the oven and bake for 25 minutes, then remove the foil and bake for 20 minutes more, or until the cheese is lightly browned and bubbly.
Finish. Remove the squash from the oven, then use a fork to scrape the flesh into strands.
Tips for Success
Here are some hints and tips for making this cheesy pesto spaghetti squash recipe:
- Add fresh herbs. If you have fresh basil, parsley, or thyme on hand, you can add it as a garnish just before serving.
- Making the “spaghetti.” When you’re ready to eat, take your fork and scrape the flesh of the squash from the stem end all the way to the bottom. This will separate it into strands.
- Brown the tops. You can turn on the broiler for a few minutes at the end of the cooking time to get the tops of the squash nicely browned. Just make sure you keep an eye on them so they don’t burn!
How to Store and Reheat Leftovers
This is a dish that’s best served fresh, but if you have leftovers, you can transfer the insides of the spaghetti squash boats to an airtight container and refrigerate for up to 3 days. Reheat the squash in the microwave and pour off any excess liquid before serving.
Can This Be Frozen?
I don’t recommend freezing this recipe. If you’re looking for a freezer-friendly dinner with a similar flavor profile, try my Lightened Up Chicken and Broccoli Alfredo.

Cheesy Pesto Spaghetti Squash
Equipment
Ingredients
- 1 (965 g) small spaghetti squash (about 1 1/2 pounds), halved and deseeded
- 3 Tbsp pesto
- ⅓ Cup (82 g) ricotta cheese
- 1 Cup (112 g) mozzarella cheese, shredded
- ½ Cup (50 g) shredded parmesan cheese
- ¾ Cup (177 ml) milk
- Salt and pepper to taste
Instructions
- Preheat the oven to 425 °F (218 °C). Set the squash halves on a baking sheet. Bake for 15 minutes. It should be slightly soft. Remove from the oven.1 (965 g) small spaghetti squash (about 1 1/2 pounds)
- Meanwhile prepare the cheese sauce. In a bowl combine the pesto with the ricotta cheese, mozzarella and parmesan. Add the milk and stir to combine. Season with some salt and pepper.3 Tbsp pesto, ⅓ Cup (82 g) ricotta cheese, 1 Cup (112 g) mozzarella cheese, ½ Cup (50 g) shredded parmesan cheese, ¾ Cup (177 ml) milk, Salt and pepper to taste
- Fill the spaghetti squash boats with the cheese sauce. Cover with aluminum foil and take to the oven. Bake for 25 minutes.
- Remove the foil and bake for 20 more minutes or until the cheese is slightly golden and bubbly.
- Take out of the oven and with the help of a fork, scrape into strands, combining with the sauce.
Notes
- I love to add some fresh thyme on top to give it some herby flavor but it’s optional.
- This dish is better when served fresh and it doesn’t refrigerate that well.