A light summer custard made with fenugreek/methi/vendhayam seeds, which have known body-cooling properties. Any raw rice will do, but the aromatic ones will bring more complexity and dimension: gobindo bhog (Bengal), ambe mohar (Maharashtra), Krishna Kamod (Gujarat), gandakashala and mullan kayama (Kerala)
Vendhaya kali can be sweetened while cooking or you can simply skip the addition of palm jaggery syrup in the cooking process and serve with the syrup on the side, so the sweetening happens in the eating. It’s a personal choice and a taste preference.
The traditional sweetener of choice is pana vellam or palm jaggery, but what's to stop you from trying patali or nolen gud when it's in season? (That's just before the summer starts).