A sweet dish by the name sandesh is mentioned in medieval Bengali literature, including Krittibas' Ramayana and lyrics of Chaitanya.
However, the ingredients of this original dish are not known.
This dish was most likely different from the modern chhena-based sandesh, being made of solidified kheer.

It is hard to determine when exactly sandesh started referring mainly to the chhena-based sweet instead of the kheer-based sweet.
But it is known that by the second half of the 19th century, sandesh commonly referred to the chhena-based sweet.
The Portuguese influence may have led to introduction of cheese (i.e. chhena) in sixteenth century.
A sweet dish by the name sandesh is mentioned in medieval Bengali literature, including Krittibas' Ramayana and lyrics of Chaitanya. However, the ingredients of this original dish are not known. This dish was most likely different from the modern chhena-based sandesh, being made of solidified kheer.
It is hard to determine when exactly sandesh started referring mainly to the chhena-based sweet instead of the kheer-based sweet. But it is known that by the second half of the 19th century, sandesh commonly referred to the chhena-based sweet. The Portuguese influence may have led to introduction of cheese (i.e. chhena) in sixteenth century.
Sandesh (confectionery)