Preheat the oven to 375°F
In a large bowl whisk the olive oil and balsamic together until thoroughly combined. Add the rosemary and squash and toss to coat and combine evenly.In a large roasting pan lined with parchment, arrange the squash in a single layer, drizzling with any remaining marinade. Sprinkle liberally with sea salt and fresh ground pepper.
Roast the squash for 30-35 minutes, stirring a few times until golden brown and caramelized. Adjust seasoning and serve.