Preheat the oven to 425º F. Cut the sweet potatoes in half and then cut each half into four equal sized wedges. Arrange the sweet potato wedges on a rimmed baking sheet and drizzle with the olive oil. Season the sweet potato wedges with salt and pepper.
Place sweet potatoes into the preheated oven and roast until the potatoes are fork tender, about 20 minutes. Remove from the oven and set aside
Preheat an outdoor grill to medium or place a cast-iron stovetop grill pan over medium heat.
Grill until golden brown on all sides about 2 minutes per side. Transfer to a platter;
Mix together salt, pepper, lime juice, zest, maple syrup, and chili powder; add oil to the mixture slowly and mix well. Brush mixture on sweet potatoes, garnish with fresh cilantro, and serve immediately.