Preheat the oven to 400°F. Cut the spaghetti squash in half lengthwise. Remove the seeds and webbing of the squash.
Drizzle the squash halves with olive oil and season with salt and pepper. Place the squash cut side down on a baking sheet.
Roast for 30-40 minutes. It will start to brown on the outside. The squash should be fork tender yet still slightly firm. Remove from the and let cool until it can be easily handled.
Use a fork to pull the flesh apart and away from the sides. The flesh will form "spaghetti-like" noodles as it separates.