Take all the millet and urad dal and grind it to a fine powder. If taken in larger quantities, you can grind it in a flour mil.
Take one cup of the flour, add enough water to make a thick batter. Cover and let it ferment for 8 hours or overnight.
To the batter add sugar and salt and mix well.
Grease the paniyaram pan with ghee, add half a ladle of batter to a mould, add a teaspoon of nutella and top with more batter. Likewise fill all the moulds of thew pan.
Cover and cook until the bottom is golden.
Gently flip the paniyaram and let it cook on the other side too.
Dust with icing sugar and serve it hot out of the pan.