Germans believe no Christmas is complete without marzipan, the mouth-watering treat made of sugar and crushed almonds that dates back to the Middle Ages.

But market pressures are driving innovation of the beloved holiday tradition -- not least in Luebeck, the charming port city in northern Germany that is arguably the world capital of marzipan.

Marzipan "has a frumpy, slightly dowdy image," said Janine Judetzki, a spokeswoman for the German marzipan firm Lemke. 

"We are anxious to make the image a bit younger and also cater to other target groups."

The delicacy was, according to Luebeck lore, invented in the 15th century and has been savoured by Prussian emperors and praised by cherished writers such as local son Thomas Mann, whose visage carved in marzipan can be seen at a museum on the city's high street.