Bake the squash: Preheat the oven to 400°F. Line a large, rimmed baking sheet with parchment paper. Grab a large, sturdy chef's knife and a cutting board that doesn't slip.
Lay the squash down horizontally on the cutting board. Using a very sharp, sturdy chef's knife, trim off the stem and base end of the spaghetti squash so that you have a flat side on each end.
Stand the spaghetti squash upright on the larger of the two ends, and carefully cut it in half lengthwise from top to bottom. Scoop out the seeds and stringy insides. You can discard the seeds or save them to roast later.
Drizzle the cut sides of the squash with 1/2 teaspoon olive oil each and then sprinkle the salt and pepper over the halves. Rub lightly to evenly coat the insides of the squash.
Place the squash cut-side down on the prepared baking sheet. Do not press any holes in the squash.
Bake for 35 to 40 minutes, until the squash is just fork-tender on the inside, lightly browned on the outside, and the skin gives a little when pressed on the outside (be careful, it is hot!). If your squash is very large, it may be as long as 50 minutes or so, but don’t let the squash overcook or your strands will be soggy.
Flip the squash over.
With a fork, fluff to separate the strands. Enjoy topped with butter and herbs, a sprinkle of brown sugar, or in any recipe calling for baked spaghetti squash (see blog post above for suggestions).
TO STORE: Refrigerate roasted spaghetti squash in an airtight storage container for up to 5 days.
TO REHEAT: Rewarm spaghetti squash in a skillet on the stovetop over medium-low heat with a little olive oil or your sauce of choice.
TO FREEZE: While you can freeze spaghetti squash, it may become very soggy once thawed. If you want to freeze leftovers, freeze them in an airtight freezer-safe storage container for up to 3 months. Let thaw overnight in the refrigerator before reheating.