Preheat the oven to 425 degrees F (220 degrees C). Line a 9x13-inch baking dish with aluminum foil; set aside.
Combine carrots, olive oil, salt, and pepper in a resealable plastic bag and seal well; alternatively, use the carrot bag. Toss to coat evenly. Pour carrots into the prepared baking dish.
Bake in the preheated oven until tender, about 30 minutes. Sprinkle balsamic vinegar over carrots; shake the dish to coat evenly. Return to the oven and continue baking until liquid is absorbed, 5 to 10 minutes. Serve hot.
