Preheat the oven to 400°F
Wash the acorn squash
Cut the squash in half lengthwise
Scoop out the seeds and stringy pulp
Place the halves cut-side down on a baking sheet
Add a little water to the baking sheet if desired
Roast for 35 to 45 minutes, until tender
Remove from the oven and let cool slightly
Scoop out the flesh or serve in the skin
Season with butter, salt, pepper, or cinnamon if desired