First start by soaking the raw rice for 4 hours, then grind it to a fine paste adding 1/2 cup water and the cooked rice. You can also add fennel seeds for a nice flavour and aroma.
Also melt the jaggery with 1/2 water and cool 2/3 min, when still warm (not hot) mix it will the rice batter.Add baking powder,cardamom and salt at this stage and allow to rest 5/10 min.
After 10 min lightly heat the mixture on a low heat for 2/3 stirring continuously, or else it will get stuck at the bottom. Heating the batter brings out a better flavour and texture to the kalthappam.
Now take your pressure cooker and add the ghee,then fry the cut shallots, coconut and cashews. Remove and keep aside. There will be some ghee left in the pan.
Mix half of the fried mix in the rice batter and save some for topping.
Pour in the rice mixture in the pressure cooker which has some ghee, add in the rest of the fried mix on top. Now place the lid with out the whistle and cook on high for 2/3 min.
After 3 min keep a very low the heat and cook for 15/20 min.
Once cooked let it rest for 15 min before you open the lid.
Now your done, hope you guys try this.