Position rack in lower third of oven; preheat to 450ºF.
Combine oil, chili powder, cumin and salt in a medium bowl. Add carrots and toss well to coat. Spread out on a rimmed baking sheet. Roast the carrots, stirring once, until tender and golden, 20 to 25 minutes
Toss the carrots with cilantro and lime juice. Serve immediately.