Preheat the oven to 400°F (200°C).
Wash the sweet potatoes thoroughly.
Cut the sweet potatoes into cubes of even size.
Toss the sweet potato cubes with olive oil, cinnamon, and a pinch of salt.
Spread the sweet potatoes on a baking sheet in a single layer.
Roast in the oven for 25-30 minutes, flipping halfway.
In a small bowl, mix maple syrup and chopped nuts.
Remove sweet potatoes from the oven and allow them to cool slightly.
Top the sweet potatoes with the maple-nut mixture and Greek yogurt.
Serve warm, garnished with fresh fruit if desired.