Set your oven to 400°F (200°C) so it can heat up while you prepare the squash. I like to start my prep while the oven preheats to save time.
Peel the butternut squash using a vegetable peeler or a sharp knife. Remove the seeds and cut the flesh into 1-inch cubes to ensure even roasting.
Place the squash cubes in a large bowl. Add the olive oil, salt, and ground black pepper. Toss thoroughly so all pieces are evenly coated.
Line a baking sheet with parchment paper. Spread the seasoned squash cubes in a single, even layer on the sheet. Roast in the preheated oven for 25-30 minutes, turning the cubes halfway through, until they are tender and caramelized around the edges.
Remove the roasted squash from the oven. Let it cool slightly before serving as a side or using in other recipes. For extra flavor, I sometimes sprinkle a touch of sea salt right after roasting.