Preheat your oven to 400°F (200°C).
Prepare the squash by peeling, seeding, and cubing it into 1-inch pieces.
In a large mixing bowl, combine the cubed butternut squash, olive oil, brown sugar, salt, cinnamon, nutmeg (if using), and black pepper.
Spread the squash mixture in a single layer on a baking sheet, ensuring they are not overcrowded.
Roast in the preheated oven for 25-30 minutes, flipping halfway through.
Check for doneness by piercing with a fork; they should be tender and slightly caramelized.
Remove from the oven and let cool slightly before serving.