This is a magical squash.
Slice it in half down the long side using your sharpest knife. Put the two halves open side down in an oven proof dish and fill it with water one inch (2-3 cm) up the sides. Bake the spaghetti squash for 35-40 min at 350F/175C until you can poke a knife through the skin. Let it cool a bit and when you can handle the heat, grab a fork and start scraping the spaghetti strings off the sides. Magical. You can top it anyway you would a regular spaghetti dish. I simply added a bit of butter, a drizzle of olive oil, grated some parmesan on top, then sprinkled with freshly ground pepper and flaky sea salt.