1.
Preheat the oven to 375 F.
Cover a large baking sheet with parchment paper.
2.
Cut the squash in half lengthwise. The easiest way to do this is, surprisingly, with a small knife. Use a sharp paring knife to carefully create a shallow slit along the top of the squash, lengthwise. Now, using a large knife, place the blade in the slit and bang the squash carefully with some force on the cutting board. It should crack along the fault line created by the small knife. Scoop out the seeds and pulp with a large spoon.
3.
Place the squash, cut side down, on the baking sheet.
Sprinkle the water on the paper around the squash.
Roast until the squash is tender but not mushy, 30–40 minutes.
Place the baking sheet on a cooling rack, and, using a hot mitt, turn the squash cut side up to cool.
4.
When it’s cool enough to handle, scrape the inside with a fork to shred the squash into gorgeous spaghetti strands. You know how you could do that?
In a hurry? You can cook spaghetti squash in the microwave, but it will not retain its al dente texture.
Place the squash, cut side up, in a microwave-safe dish along with 1/4 cup of water.
Cover with plastic wrap and cook on high for 10–15 minutes, depending on size.