Preheat the oven to 425 F (220 C). Line a baking sheet with parchment paper or lightly oil it.
In a large bowl, whisk together the olive oil, honey, salt, pepper, cinnamon and smoked paprika if using.
Add the sweet potato cubes to the bowl and toss until all pieces are evenly coated with the honey-spice mixture.
Spread the potatoes out in a single layer on the prepared baking sheet, leaving a little space between pieces so they roast instead of steam.
Roast for 20 minutes, then use a spatula to flip the pieces. Return to the oven and roast another 10 to 15 minutes, until edges are caramelized and the potatoes are tender when pierced with a fork.
Remove from the oven and drizzle with the lemon juice or apple cider vinegar. Toss gently to coat and brighten the flavors.
Transfer to a serving dish, sprinkle with chopped herbs, and serve warm.