Place the squash on its side and slice off both ends using a sharp knife. Use a peeler to remove the skin. Cut the neck of the squash off and remove the seeds and pulp. Slice it into rings and then into cubes.
To roast the squash:
Preheat oven to 425 degrees F. Place prepped squash, olive oil, rosemary, salt, and prepper on a baking sheet. Toss to coat.
Roast for 15 minutes. Toss squash and continue to roast for 5 more minutes. Sprinkle with parmesan cheese and roast for 3-5 more minutes until cheese is melted.