In a small bowl, whisk together the liquid smoke, soy sauce, maple syrup, onion and garlic powder. Place the carrots in a shallow baking dish and pour over the liquid mixture. If you have the time, cover and let them marinate for at least 2 hours. If not, that’s okay, just roll the carrots around in the mixture, using your fingertips to massage the marinade into the carrots. When the carrots are coated in the mixture, season with pepper and transfer to the baking sheet. Roast for 35 minutes or until fork tender. Every five minutes, brush the carrots with the remaining marinade mixture.