2. Place the cubed sweet potatoes in a large bowl. Whisk together the olive oil, agave nectar, and salt and pepper in a small bowl. Pour the mixture over the sweet potatoes and toss. Make sure the potatoes are well coated. Add the fresh rosemary and toss again.
3. Line a large baking sheet with foil and spray with cooking spray. Spread out the potatoes on the baking sheet. Bake for 45-50 minutes. Stir the potatoes every 15 minutes. Make sure the potatoes are soft. Serve warm.