Line baking sheet with parchment paper.
Drizzle olive oil on each half. (amounts vary)
Sprinkle salt and pepper. (amount according to preference)
Place squash halves cut side down on prepared baking sheet.
Roast until squash is tender and easily pierced with fork, about 50-60 minutes.
Remove from oven and cool slightly until you are able to handle it.
Scoop out squash flesh into bowl and mash with fork or potato masher until almost smooth.
Top with butter, salt and pepper to taste.
Cooking time varies based on squash size. This cooking time was for medium-large squash.