Here is the recipe I use....YUM!
Spaghetti Squash Prep:
Slice in half with a large knife. Place open side down in an oven safe dish with a small amount of water in the bottom. Bake at 350 until squash is easily pierced by a knife. Let it cool until it can be handled and use a fork to scrape out the spaghetti awesome-ness!
And this is optional but I almost always add a pound of ground beef I cooked and drained to the sauce
While squash is baking place all sauce ingredients minus the Parmesan cheese in a pot. Cook together until onions start to tenderize. Once they are tender add in the Parmesan cheese, ground beef and combine.
Now you'll need the squash, sauce and ricotta cheese...and your baking dish. Start with a layer of sauce, then squash then small dollops of ricotta...repeat until dish is full.