Preheat oven to 400ºF. Line baking sheet with parchment paper. Cut spaghetti squash in half lengthwise, from stem to bottom. Scoop out seeds. Rub spaghetti squash halves with olive oil, and sprinkle with ½ teaspoon salt and ¼ teaspoon pepper, if desired.
1 large spaghetti squash, 1 tablespoon olive oil, ½ teaspoon kosher salt, ¼ teaspoon ground black pepper
Place cut side down on prepared baking sheet and bake 35 to 40 minutes, or until fork tender (see note).
Using a fork, separate strands, gently pulling them away from the sides of the shell, to form "spaghetti."
In a large mixing or serving bowl, combine squash, butter, cheese, herbs, pepper and salt, to taste. Toss lightly until combined.
1 tablespoon butter or ghee, melted, ½ cup grated Parmesan cheese, ¼ cup fresh minced herbs, ¼ teaspoon coarse ground black pepper, ¼ teaspoon kosher salt
Serve immediately.
Notes
Choosing a squash: Spaghetti squash come in various sizes. You can use one large squash or two medium-sized squash. Generally, the size doesn't affect the baking time because the thickness of the squash is about the same, no matter how large the squash is. Yield will depend on the size of the squash you use.
Cooking tip: Try not to overbake the squash. I've found that if you bake it too long, the squash becomes more mushy and doesn't separate as well into strands. It still tastes great but loses some of the "spaghetti" quality.
Herbs: I recommend fresh basil, parsley, dill, oregano, or chives, or any combination. If you choose dried herbs, use less. I like to use my pizza seasoning!
Alternative ways to cook squash: Spaghetti squash can be cooked in your microwave, slow cooker, or Instant Pot, too. Learn how to cook spaghetti squash (5 methods).