01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper to facilitate cleanup.
02 - Halve the squash lengthwise and scoop out the seeds using a large spoon.
03 - Brush the cut sides of the squash generously with olive oil. Season with kosher salt and freshly ground black pepper.
04 - Place the squash halves cut side down on the prepared baking sheet. Roast for 35 to 40 minutes until the flesh is tender when pierced with a fork.
05 - While the squash roasts, combine the softened butter, brown sugar, cinnamon, and nutmeg in a small bowl. Mix until smooth and well incorporated.
06 - Remove the squash from the oven. Carefully flip the halves so the cut side is facing up. Spoon the brown sugar butter mixture evenly over each squash half.
07 - Return the squash to the oven and roast for an additional 5 to 7 minutes until the butter is melted and bubbly.
08 - Transfer the squash to a serving dish. Serve hot, spooning any remaining glaze from the baking sheet over the top.