
Place a rack in the center of your oven and preheat to 375°F.
Arrange the sweet potatoes in a 9x13-inch baking dish (no greasing needed).
In a small saucepan over medium heat, melt the butter. Add the maple syrup, salt, cinnamon, ginger, and nutmeg. Stir well and bring to a gentle simmer for 5 minutes to combine the flavors; it will only reduce a little bit.
Pour the butter mixture over the sweet potatoes in the baking dish and stir to coat.
Cover with aluminum foil. Bake the candied sweet potatoes for 40 minutes, stirring at the 20-minute mark. Uncover, stir once more, then continue baking for 20 minutes more, until the potatoes are glazed and fork-tender.
Remove from the oven and sprinkle with herbs. Let cool for 10 minutes before serving. The sauce will thicken up as it cools.