Heat oven to 400° F.
On a rimmed baking sheet, combine the carrots, 2 tablespoons of the oil, the pine nuts, 1/2 teaspoon salt, and 1/4 teaspoon pepper and spread into a single layer. Roast until the carrots are tender, about 30 minutes.
Meanwhile, segment the orange by cutting away the peel and white pith. Next, cut on both sides of each segment, freeing the segments from the membrane. Place the segments in a bowl, then squeeze the membranes over them to extract any remaining juice. Stir in the cumin, scallions, and the remaining oil.
Arrange the carrots on a platter and spoon the orange mixture over the top. Serve hot or at room temperature.