Grate the jaggery and add it to a pan with 3 to 4 tbsps water. Heat it until the jaggery dissolves. Place a filter over a glass and pass the jaggery syrup through it. Rinse the pot and add back the jaggery syrup to it. Boil this until the syrup thickens a bit. Cool this completely and set aside.
Add saggubiyyam to another pot and rinse them well twice. Pour 1½ cups water and cook them until they turn transparent. You can also bite them and check they must be fully cooked and not be hard inside. If needed add more water and keep stirring until done.
Pour milk and cook until it thickens. Stir in the cardamom powder and cooled jaggery syrup. Do not pour hot jaggery syrup to the cooked saggubiyyam otherwise the payasam will curdle completely.
Heat 1 tablespoon ghee in a small pan. Add split cashews and fry until they turn lightly golden. Then stir in the raisins and fry until they turn plump. Pour this to the saggubiyyam payasam.
Always cool the foods before offering to god. Sagubiyyam payasam is served after cooling completely to have the cooling effects on the body.