Preheat oven to 425°F. Line a rimmed baking sheet with foil. Cut sweet potatoes into 1/2-inch-thick wedges. Place on the prepared baking sheet, drizzle with oil and toss well. Spread out in a single layer. Bake until tender when pierced with a knife, 25 to 30 minutes. Season with salt and pepper.

Meanwhile, combine vinegar and honey in a small saucepan. Bring to a boil over medium-high heat and cook until syrupy and reduced to 1/3 cup, 12 to 15 minutes. (Watch the syrup carefully during the last few minutes of reducing to prevent burning.) Swirl in butter. Drizzle the sauce over the sweet potatoes.