Just about any way you can think of to apply heat can be used to cook spaghetti squash. The big question is: to cut or not to cut before cooking? You can do it either way. Here are the pros and cons of each. (Cooking times will vary with the size of the squash/pieces of squash.)
Cutting Up Spaghetti Squash Before CookingAdvantages: It cooks faster.
Disadvantages: Like any winter squash, hacking it up takes muscle and a sharp knife or cleaver. It's also a bit more work to scrape out the seeds and pulp when they are raw.
Method: Just get in there and cut it in half (lengthwise) or quarters. You don't want to cut it up too small unless you want short strands. Scrape out the seeds and pulp as you would with any squash or pumpkin.
Bake rind side up about 30 to 40 minutes at 375 F.
Microwave 6 to 8 minutes (let stand for a few minutes afterwards)
Boil 20 minutes or so.
Separate strands by running a fork through in the "from stem to stern" direction.
Cooking Spaghetti Squash WholeAdvantages: It's easier.
Disadvantages: It takes longer to cook, and you need to watch out for burns when removing the pulp and seeds.
Method: Pierce the squash several times with a sharp knife. (Do this especially if you're microwaving it, or you may end up with a "Squash Explosion.")
Bake about an hour in the oven at 375 F.
Microwave 10 to 12 minutes, then let stand for 5 minutes or so afterward to finish steaming.
Boil for half an hour or so.
Slow Cooker/Crock Pot: Put it in with a cup of water and let it go on low all day (8 to 10 hours).
When done, cut open "at the equator" (not lengthwise), remove seeds and pulp (I use tongs and an oven mitt -- it is HOT) and separate strands with a fork.
Did You Know? Any squash seeds can be roasted just like pumpkin seeds (pumpkin is a kind of squash). They are low-carb, nutritious, and delicious: How To Roast Pumpkin or Squash Seeds