Boil and mash the Sweet potatoes with a fork.
Mix the Sweet potatoes and Jaggery so that the Jaggery is almost dissolved in Sweet potatoes.
Add in the Wheat flour, Cocoa powder, baking powder and salt. Mix everything.
Add vanilla essence and slowly add milk to get a lump free batter. Consistency of the batter should not be too runny, but one should be able to spread it.
Let it rest for 5 minutes.
Heat a non stick pan with and grease it with butter. Pour a spoonful of batter onto the hot pan and spread it to the size and thickness as desired. If the batter is thick it becomes a little difficult to spread it out. In that case just add 1-2 spoons of batter and let it take the shape.
Cook it on a slow until golden brown from below around 5-6 minutes. Reverse it and cook it on the other side.
Serve it warm with honey or chocolate sauce or enjoy as is.