Using a knife, poke 10 to 15 holes in the spaghetti squash to vent.
Add 1 cup of water to the Instant Pot and insert a trivet.
Place the spaghetti squash on the trivet. Close the lid. Select Pressure Cook and cook the squash on high pressure for 22 minutes. If your spaghetti squash is on the larger side, cook for 25 minutes.
After the cook timer beeps, let the pressure release naturally for 10 minutes. Then, turn the steam release valve to Venting to release any remaining steam. It is helpful to use a wooden spoon for this to avoid burns.
Once the floating valve drops, carefully remove the lid. Let the spaghetti squash cool in the Instant Pot for about 5 minutes.
Using potholders or oven mitts, carefully lift the trivet with the spaghetti squash from the Instant Pot. Roll the spaghetti squash off the trivet onto a cutting board.
Holding the spaghetti squash with a towel (it will still be very hot!), carefully slice the squash across the middle at the narrowest part, creating two short halves (this results in longer noodles than when you slice it lengthwise).
Use a spoon to scoop out the seeds from each half. Don’t worry if you can’t find them all—you can spot and remove any strays on the next step.
Using a fork, gently scoop the cooked squash out from the skin into a large bowl. The strands will resemble spaghetti and should have an al dente feel.
Gently swirl the strands in the bowl with a fork to check for and remove any remaining seeds before serving.
