Preheat the oven to 425 degrees F.
Mix the olive oil, brown sugar, and maple syrup together in a small bowl. Put the acorn squash, cut side up, in a single layer on a baking sheet. Brush the glaze on the flesh of the squash and season with salt, and pepper, to taste.
Put the squash in the oven and roast it until tender and golden brown, about 40 to 45 minutes. Remove the squash from the oven and transfer it to a serving dish. Top with butter and serve.