Grate carrots. See notes for more information.Heat clarified butter in a heavy pan. Add grated carrots and stir constantly till carrots are very tender.Add condensed milk and stir well. The mixture will appear to liquefy slightly.Add cardamom powder, chopped nuts and raisins.Lower heat to medium and keep stirring till liquid has evaporated and carrots are mostly dry.Add sugar if desired.Serve warm or chilled.