Wash and soak urad dal in a bowl with enough water. And do same with rice too. Keep these for 3 to 4 hours.
After 4 hours, grind the urad dal to a smooth paste. And grind the rice to a coarse paste.
In a big bowl add urad dal and rice paste and mix properly. Keep it out of the fridge for 4 to 5 hours for self fermentation. After fermentation the batter will rise. So it is better to keep in a big bowl.
Break and mash jaggery or grate the jaggery. Clean, peel and crush the ginger.
Take a baking pan, grease with little ghee and dust with maida. And keep aside.
Now add everything together in the batter except ghee. Mix properly.
Preheat the oven in 200 degree Celsius for 7 mins. Pour the batter in the baking pan and bake for 30mins in 180 degree Celsius. After 15mins bring out the pan and brush the above surface with ghee. After 30mins repeat the process.
If not done after 30 mins bake for some more time, up to the knife come out clean. Bring out of the oven and allow to cool down completely. Then demould it.
It can be done in a kadai too. Add 1 1/2 tbsp of ghee in a heavy buttom kadai and heat it. Pour the batter and keep on the slow flame and cover it and cook. It should be cooked up to the knife comes out clean. Cool down completely and serve according to your choice