Kadala Pradhaman is a dessert recipe for the Kerala feast of Sadya, which is made with chana dal / split garbanzo lentils, jaggery and coconut milk. This is one of the most popular recipes for a sadya, only second to maybe Ada Pradhaman.
The 2 tbsp water is added to the jaggery so there is something in the pan other than the jaggery till it starts to melt, otherwise it might caramelize and burn.
Remove the payasam right after you add the coconut cream. Otherwise the oil will separate from the coconut cream, because of its higher fat content, and that will leave a bad after taste to the payasam.