What’s the science behind thenkuzhal (its a crispy snack, crispy hollow tubes)? How/why does the hollow form inside this crispy snack? It is made from rice flour dough. For more details please check https://kalaskalai.wordpress.com/2015/12/20/thaenkuzhal-murukku/
I think the hollow comes from air expanding while frying the dough.
At first I thought it was made like an Italian bucatini (with a die), but watching videos showing how Thaenkuzhal is made, I think it's only air expanding