Puree the cooked carrots with a blender or immersion hand blender. If necessary, put the pureed carrots into a fine sieve and push out any excess water.
Weigh out 2 cups (400g) of the pureed carrot and discard the rest (though it's great to add to soups, stews or mixed with maple syrup and added to porridge).
Put the carrot puree, grated carrot and sugar into a large saucepan. Add the granulated sugar and, while stirring constantly, bring to the boil for five minutes.