Home How To's How to Cook Spaghetti Squash (Instant Pot, Slow Cooker, Oven, or Microwave)

How to Cook Spaghetti Squash (Instant Pot, Slow Cooker, Oven, or Microwave)

By Jess Smith

Published Oct 16, 2018•Updated Nov 01, 2020

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Squash season is in full swing and we are plowing through all the varieties in serious quantities. My four year olds will reliably eat squash over any other type of produce, so I’m on the hunt for any and all ways to use them. (Got a good one!? Please tell!!)

Butternut squash is always a favorite, but this year we’ve been on a spaghetti squash kick. The novelty of the squash “noodles” goes over well with the kids, and if the squash is cooked just right, I can even trick myself into thinking I’m eating all the carbs.

I wanted to just write a straightforward blog post with some tips for making it a bit easier to carve into a spaghetti squash and roast it, but then I realized this is was worthy of a head-to-head squash cook-off. What kind of food blogger would I be if I didn’t do a semi-scientific comparison that involved a mountain of spaghetti squash cooking simultaneously in four different ways (and my kids’ babysitter going all wide-eyed when she walked into the kitchen)?

Scroll down for instructions to cook spaghetti squash in the Instant Pot, slow cooker, oven, and microwave plus I’ll tell you my favorite method at the end!

Tips for Preparing Spaghetti Squash

1. 1. 1. Choose firm, unblemished squash with the stem intact. Look for squash that is firm and feels heavy for its size. Make sure it doesn’t have any soft or brown spots. Make sure the stem is intact and feels firm.
      2. Microwave to soften (optional). This step is optional, but can soften the squash to make it easier to slice. Poke the flesh of the squash with a knife 6 to 8 times and place the whole squash in a microwave-safe dish. Microwave on high for 4 to 5 minutes, until the flesh has a bit of give to it when you press it with your thumb. (Note: I have found that with good knives, and by slicing through the narrow portion of the squash as mentioned below, there’s no need to microwave the squash first. If you do find that you need to soften it in the microwave first before slicing, it’s a good idea to reduce the cook times listed below by roughly 1/4 so the squash strands don’t get too tender.)
      3. Slice in half. Use a good, sharp knife to slice the squash in half. You can slice the squash either way you’d like. Many recipes recommend slicing from stem to base, but I slice my squash the other way (down the more narrow center) for two reasons:
         • • It’s easier. There’s less to slice and a more natural place for your hand to rest while holding it in place.
           • You get longer strands. If you want long strands like real spaghetti, this is absolutely the way to slice it. Cutting from stem to base slices all of those strands in half. (My friend Beth at Pass The Plants gets all scientific about long squash strands here.)
      4. Scrape out seeds. An ice cream scoop works great for this!

Cooking Squash Whole vs. Sliced in Half

I always recommend slicing the spaghetti squash in half before cooking it. I know that many people swear by cooking the squash whole, but I would argue that there are a few reasons to slice it in half first. For one thing, it’s much easier to scrape the seeds out of a firm, uncooked squash. Seeds tend to sink into tender, cooked squash strands. Even more importantly, it’s helpful to be able to test a few strands for tenderness as the squash is cooking (in the slow cooker, oven, or microwave) – something you can only do if the squash is sliced open.

If cooking in the Instant Pot, you may not have a choice – a 3 lb squash will only fit in my Instant Pot if sliced in half.

Note: If you’re going to serve the squash strands inside the squash, like a squash “bowl”, slice the stem off as well so the squash will sit upright.

Spaghetti Squash in the Instant Pot

To cook a (3 lb) spaghetti squash in the pressure cooker / Instant Pot:

1. 1. Slice spaghetti squash in half and remove seeds (as noted above).
   2. Place the steamer rack in the bowl of the pressure cooker.
   3. Add 1 cup water.
   4. Add spaghetti squash halves, cut-side up.
   5. Close and lock the lid.
   6. Set the pressure cook manual setting on high for 7 minutes.
   7. Manually release the pressure.
   8. Remove squash halves and use a fork to loosen the spaghetti squash strands.

Spaghetti Squash in the Slow Cooker

To cook a (3 lb) spaghetti squash in the slow cooker:

1. 1. Slice spaghetti squash in half and remove seeds (as noted above).
   2. Add 1 cup of water to the bowl of the slow cooker.
   3. Add spaghetti squash halves, cut-side up.
   4. Cook squash on high for 3 to 4 hours or low for 5 to 6 hours (check the squash strands to see if they are tender when you reach the low end of the range listed and continue cooking if needed).
   5. Remove squash halves and use a fork to loosen the spaghetti squash strands.

Spaghetti Squash in the Oven

To cook a (3 lb) spaghetti squash in the oven:

1. 1. Preheat the oven to 400 F / 204 C.
   2. Slice spaghetti squash in half and remove seeds (as noted above).
   3. Brush a sheet pan or baking dish with some oil.
   4. Place squash cut-side down on the prepared pan / dish.
   5. Roast squash for 35 to 45 minutes (check the squash strands to see if they are tender when you reach the low end of the range listed and continue cooking if needed).
   6. Allow squash to cool and use a fork to loosen the spaghetti squash strands.

Spaghetti Squash in the Microwave

To cook a (3 lb) spaghetti squash in the microwave:

1. 1. Slice spaghetti squash in half and remove seeds (as noted above).
   2. Place squash cut-side down in a microwave safe baking dish.
   3. Pour water into the dish to about 1″ / 2.5 cm depth.
   4. Microwave on high for 5 to 12 minutes, checking the squash at 1 minute intervals when you reach 5 minutes to see if the squash strands are tender. (Note: if you pre-cooked the squash to make it easier to slice, it should be done in the lower end of the range.)
   5. Allow squash to cool and use a fork to loosen the spaghetti squash strands.

My Favorite Method

Okay you guys, I know I’ve been on a bit of an Instant Pot kick lately (and it’s not going to end any time soon), but I am totally hooked on using the pressure cooker to cook spaghetti squash. 7 minutes in the Instant Pot and then using manual release has been giving me perfect, tender spaghetti squash strands every time.

I used to exclusively roast my spaghetti squash because I *thought* it gave the squash more flavor. But then I realized something. Unlike other squash varieties, spaghetti squash doesn’t have much flavor no matter how you cook it! Ha! That’s what makes it such a great blank slate for other recipes. Microwaving is a close runner-up and great because you can take the squash out, check for tenderness, and then keep cooking it. The fastest cooking method really might be the best when it comes to spaghetti squash.

Cooking Small or Large Squash

In testing, I used a spaghetti squash that was as close to 3 lbs as I could find so that I got consistent results. This seems to be a fairly common size in most places I shop. If using a smaller or larger squash, adjust the cooking times slightly (and check more frequently if using any method other than the Instant Pot). If using the Instant Pot, I’ve found that 7 minutes yields tender squash strands for squash that is anywhere from 2 to 5 lbs (pressure cooking for the win!). For all of the methods, you could also cook a second 3 lb spaghetti squash at the same time to give yourself even more of those spaghetti-like strands.

Happy squash season!

Yummy Spaghetti Squash Recipes

• Spaghetti Squash Bowls with Marinara and Italian Sausage
• Spaghetti Squash Egg Nests

Favorite Tools

• 6-inch Global Knife 
• Half Sheet Pan 
• KitchenAid 6-Quart Slow Cooker
• 6-Quart Instant Pot Duo

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