Preheat your oven to 425°F (220°C).
Wash and peel the sweet potatoes, then cut them into 1-inch cubes.
In a large bowl, combine the cubed sweet potatoes, olive oil, brown sugar, cinnamon, salt, and black pepper.
Spread the sweet potatoes in a single layer on a baking sheet.
Roast the sweet potatoes for 25-30 minutes, stirring halfway through.
Check for doneness by piercing with a fork; they should be tender and fully cooked.
Remove from oven and let cool for a few minutes before serving.