Preheat your oven to 400°F (200°C).
Line a baking sheet with parchment paper or foil for easy cleanup.
Place the sweet potato cubes in a large bowl. Spray lightly with cooking spray or toss with olive oil.
Add garlic powder, paprika, cinnamon (if using), salt, and pepper. Toss until evenly coated.
Spread the potatoes in a single layer on the baking sheet.
Roast for 30–40 minutes, flipping once halfway through, until tender and slightly crisp on the edges.
Garnish with fresh herbs, if desired, and serve hot.