1/4cupfreshly grated Parmesan cheeseplus more for topping
Preheat oven to 350 degrees.
Cut bottom of squash and cut squash in half lengthwise. Remove seeds.
Place squash, cut sides down, in a large rimmed baking dish. Pour water into dish around squash halves, until half way up the sides of the squash.
Bake for 45 minutes, or until flesh is fork tender.
Remove squash from oven and turn oven up to 375 degrees.
Let squash cool for 10 minutes. Scoop out flesh of the squash, being careful to leave one shell of squash intact, Mix the flesh of the squash with butter, salt, pepper, and cheese.
Scoop mixture back into one half of the squash. Sprinkle with more cheese and return to oven.
Bake for 20 minutes, or until cheese is golden and melted.
To Prepare in Advance: Bake the butternut squash as directed. Once the squash has cooled, remove flesh and make Parmesan Mash. Re-stuff Butternut Squash Half and place in large baking dish. Cover well with plastic wrap and refrigerate for up to 2 days. On day of serving, remove squash from fridge while oven is preheating to come to room temperature. Bake at 375 degrees for 30-40 minutes or until warmed through.