Preheat oven to 425 degrees F. Line a large rimmed baking sheet with parchment paper.
Arrange carrots in an even layer in the prepared pan. Cover with foil. Roast for 30 minutes.
Meanwhile, stir brown sugar, butter, cinnamon, salt, cloves (if using) and cayenne in a small bowl until well combined.
Spoon the glaze mixture over the carrots and stir to coat well. Roast, uncovered, until the carrots are tender and glazed, about 10 minutes. Top with pecans.