Take large baking dish and spray with non stick spray.
Wash squash and pat dry. Slice length ways in half. Score the flesh side with a fork. Place skin side down in pan.
place chopped onion onto each squash. (the amount you put is your preference. I put a lot because I love onion). Season each piece with salt, pepper and garlic powder. Drizzle each piece with soy sauce and you can lightly drizzle a little olive oil or canola oil over each squash.
Sprinkle shredded Parmesan cheese over each squash.
Place a little water on bottom of pan (to help steam the squash). Cover the pan with foil. Place in oven and bake for 1 hour at 400*. Remove foil and broil until squash brown a little on top.