Wash and soak moong dal in three cups of water for five to six hours. Wash raisins and pat them dry. Break khoya into tiny granules. Drain dal, grind to a coarse paste and keep aside. Heat two tablespoons of ghee in a kadai, fry cashewnuts and raisins and keep aside.
Heat sugar and one-fourth cup of water till sugar dissolves completely. Strain and heat mixture again till syrup reaches a two-string consistency. Heat remaining ghee and fry dal paste over medium heat till it leaves the sides of the kadai.
Add khoya and cook for five minutes, stirring continuously. Pour in syrup and continue to cook for seven to ten minutes till the mixture gets a fudge like consistency.
Add rose water and pour mixture onto a greased plate and spread evenly. Decorate with cashewnuts and raisins. When set, cut into square or diamond shaped pieces.