For a smoother marmalade, use a food processor to finely grate the carrots. Adjust the amount of cardamom to your preference. Start with 3/4 teaspoon and add more to taste. The marmalade will thicken as it cools. Do not overcook, or it will become too hard. Sterilize your jar before filling to ensure a longer shelf life. Serve this marmalade with cream cheese and crackers, or a grilled cheese sandwich with brie.