Blend together bananas and jaggery powder with little milk in the mixer till smooth and lump free. .
Take wheat flour in a bowl. Add above puree, oil, vanilla essence and rest of the milk.
Make a smooth batter and leave it for 10 to 15 minutes. The batter should be like Dosa batter. Adjust milk accordingly.
Heat a griddle, brush oil on it. Lower the flame and put a ladle full of the batter. Spread it lightly.
Increase the flame, apply little oil around the edges and after a minute or so, flip it and cook from the other side too.
When golden brown from both the sides, serve it or stack one by one.
Serve with caramelized bananas and honey.
You can even serve these with chocolate sauce or caramel sauce.