Preheat oven to 400 degrees. Using a chef's knife, cut the squash in half. Spoon out the seeds and discard. Lay a sheet of foil on a baking sheet and put the squash cut side up. Place a pat of butter in each cup of the sqaush. Sprinkle sugar in the raw, salt and pepper on to the squash. Roast the butternut squash for 30-45 mins. Check after 25 minutes. You want the squash to be soft. If not soft, continue to cook. This is a good time to make the glaze/sauce, see below.
Allow squash to cool slightly and then using a hand towel to hold the hot squash, spoon out all of the flesh away from the skin into a mixing bowl. Discard skins. Use a fork to mash the squash.
Fold the glaze/sauce into the mashed squash, thoroughly incorporating the sauce into the mixture.
Place the mashed butternut squash into an oven safe dish and bake on 375 for 15 to 20 minutes or so prior to serving. This allows the the sugars to caramelize for ultimate deliciousness.