1. Prepare the Spaghetti Squash for Cooking
First, choose a spaghetti squash that feels heavy for its size. Then decide if you want to cook it whole or halved. It is easier to cook it whole, but takes longer.
To cook spaghetti squash whole: poke it all over with a fork so steam doesn't build up too much inside (no wants to clean up exploded squash). Whole squash can also be microwaved (see below).
To cook spaghetti squash halved: cut off and discard the stem end and cut the squash in half lengthwise. Spaghetti squash are big; this will take a large knife and a bit of brute strength. Use a large spoon to scrape out the seeds and attached strands. Lay halves cut-side-down on a lightly oiled baking sheet.
2. Roast or Microwave the Spaghetti Squash
I prefer roasting winter squash — but then I live in a cold house and having the oven going often sounds like a great idea.
To roast spaghetti squash: Preheat oven to 375°F and set whole or halved squash in the oven. Cook until a fork inserts easily through the skin and into the flesh of the squash, 60 - 90 minutes for whole squash, 45 - 60 minutes for halved.
To microwave spaghetti squash: Set whole spaghetti squash in the microwave and cook on high power for 5 minutes. Repeat with 2-minute increments until a fork inserts easily through the skin and into the flesh of the squash, up to 30 minutes total depending on the power of your microwave.
3. Cut Spaghetti Squash Open
If you cooked the spaghetti squash whole, you'll need to cut it open. If you cooked it halved, skip to step 5.
Cut off the stem end and then cut the spaghetti squash in half lengthwise. Since it's cooked, you won't meet a lot of resistance, so even weaklings like me can do this easily. A big knife is handy, though, just because spaghetti squash tend to be so large.
Note that the squash will be hot and a lot of steam will come out as you cut it.