Preheat oven to 400 degrees F. Lightly grease a baking sheet or roasting pan. Spaghetti squash can be roasted as 2 halves OR each half can be sliced into 4 pieces to reduce roasting time. Drizzle olive oil over flesh of the spaghetti squash and spread with a spoon or hand for even coverage.Place spaghetti squash, cut sides down, on the prepared baking sheet, and bake for 30 to 45 minutes in preheated oven, or until a sharp knife can be inserted with only a little resistance. Remove squash from oven, and set aside to cool long enough to be easily handled. Use a large spoon to scoop out the stringy pulp from the squash, and place in a medium bowl. Toss to taste with salt and pepper and additional olive oil or other favorite spices if desired.