The time it takes to cook spaghetti squash at 425 F in the oven is 45 minutes.
Preheat your oven to 425 F while you're preparing your spaghetti squash and then place the spaghetti squash into the oven for 45 minutes.
Then check the spaghetti squash and it should be fully cooked and ready to eat after cooling down.
You should place some tin foil or aluminum foil in the baking sheet you're cooking the squash in so that you can flip the spaghetti squash over after 15 minutes of it being in the oven.
However you don't have to do that if you don't want too.
You can just allow the spaghetti squash to cook in the oven for up to 45 minutes.