Cooking Squash in Microwave: Cut the squash in half lengthwise, and scoop out the seeds. Place squash in a microwaveable dish with the open side up. Add a few cups of water, and cover with saran wrap. Microwave for 10-12 minutes. Let it sit for 5 minutes covered, then test it with a fork to see if it is done, (squash should be tender and pull apart in spaghetti-like strands). If needed, cook an additional 2-5 minutes (cook time varies based on size of squash). Remove from oven and allow to cool, until it can be handled. Using a fork, loosen the spaghetti squash.
Cooking Squash in Oven: Cut the squash in half lengthwise, and scoop out the seeds. Place squash cut side down in a baking pan. Bake the spaghetti squash in the oven at 350 F for 45 minutes. Remove from oven and allow to cool, until it can be handled. Using a fork, loosen the spaghetti squash.
Spray a non-stick skillet with cooking spray. Add the cooked spaghetti squash “noodles” to the pan, and add garlic powder, salt, and pepper (along with other seasonings if you choose). Let squash cook for about 2-3 minutes, stirring constantly until squash has become more tender and excess moisture has cooked out of squash.
Add Parmesan cheese to the squash and cook for another 2-3 minutes, until the Parmesan starts to become brown and crispy. Remove from pan and add spaghetti sauce (if desired you can microwave sauce before serving for 1-2 minutes). Mix well and serve warm.