Take dosa batter in vessel and add cocoa powder and Hershey's chocolate syrup in it.syrup adding is your concern.if you like sweet add more.

Then add salt.mix it well.then add one tablespoon oil in it.

Now add this better in greased idli plates then steam your idlis for 10-15 minutes.when idlis are hot that time only you create faces of smiles on idlis and again give steam for 2-3 minutes.