Cut squash: Use a sharp knife to cut the spaghetti squash in half widthwise. A lot of people cut squash lengthwise, but I like widthwise for longer strands.
Scrape out seeds: Scrape out the seeds from each half of the squash with a spoon. Discard or roast them up like you would pumpkin seeds.
Add water and squash to Instant Pot: Add 1 cup of water and a trivet or steamer rack into the Instant Pot. Place spaghetti squash halves on the trivet and close the lid.
Pressure cook: Use the pressure cook function or manual to cook on high pressure for 6-8 minutes. 6 minutes will result in al dente noodles, but 8 minutes will give you a soft, but not mushy texture. The Instant Pot will take about 10 minutes to pressurize so keep that in mind when planning your spaghetti squash prep time! Once the timer goes off, use the vent to carefully quick release the pressure. Once pressure is released, carefully open the lid.
Make strands: Carefully remove spaghetti squash from Instant Pot, discarding any water that may have collected inside the squash. Once squash is cool enough to handle, pull the flesh away from the skin with a fork to create long “spaghetti-like” strands.
Serve: Serve the squash with your favorite sauce or use in a recipe that calls for cooked spaghetti squash.
Store: Cooked spaghetti squash will last 3-5 days in the fridge in an airtight container or wrapped in plastic wrap. For freezing, store in airtight freezer bags for up to 8 months.