Preheat your oven to 350 degrees F.

Wash and dry the squash, then place it on a cutting board, then use a sharp knife to cut the squash in half lengthwise (from the top of the squash down). Scrape out the seeds and stringy pulp.

Place the halves into a baking dish or baking sheet, with the cut side up (flat side up like in the pictures), then add some water to the bottom of the pan (about 1 cup, enough water to cover the bottom of the pan).

To the hollow center of each squash half, add 2 tbsp of butter, 1 tbsp of brown sugar and 1 tsp of rosemary.

Cover the squash halves in tin foil.

Bake for about 2 hours. Some squash cooks longer than others, depending on the density of the squash. Just check them at the 1 hour mark to see if the flesh is soft and roasted.

After the squash is done roasting, use a spoon to scoop out the cooked flesh of the squash, and transfer it to a bowl. Make sure to scoop out the butter and sugar mixture with the squash!

Use a mixer or hand blender to purée the squash (make sure to get the melted butter, sugar and rosemary in there) and enjoy as a side dish.