To start, preheat your oven to 375 F.
Cut the squash in half lengthwise. Using an ice cream scooper or spoon, scoop out the inside of the squash, seeds and all. Set the seeds aside to roast those separately, if you wish.
Brush the halves with a little olive oil, around 1/2 teaspoon per half. Season with salt and pepper.
On a baking sheet lined with parchment paper, place the squash halves, cut side down.
Bake for about 45 minutes, and remove from oven. Flip the squash halves cut side up again; they should be browned and steaming hot. Poke with a fork a bit to make sure they are fully cooked. The flesh should be stringy and soft. If the squash is not quite soft, put back in the oven for another 5-10 minutes.
Start scraping the squash flesh with a fork, over and over. Continue with each half until all of the squash is in spaghetti-like strands. You can season the squash and eat it directly out of the skin if you wish, or transfer it to a bowl. Add marinara, pesto, or a sauce of your choice. Store in an airtight container in the fridge for 2-3 days.