Ellu Unda also spelled Ellunda refers to one of South Indian sweets which are actually ball-shaped sweetened Sesame sweets. They are Sesame seed Balls which are made from roasted Sesame seeds called Ellu in Malayalam cooked with melted Jaggery, then shaped into small balls. 

Ellu Unda is best served with hot tea during afternoon snacks. I have eaten some during my train ride going to Kanniyakumari in Tamil Nadu

Unda is Malayalam word for balls, hence this sweet treat is called Ellu Unda in Malayalam

Sesame Seeds is called Linga in Filipino and is also cooked by some like Ellu Unda, that is Roasted then cooked with Brown sugar or Muscovado. 

Below are two (2) pictures of Ellu Unda, one from Allepey and the other one from Trivandrum, the capital of Kerala, respectively