A process of making durian ice mooncakes. [Photo/VCG]

The Peninsula Shanghai hotel is also joining the fray with a new handmade durian mooncake, an upgrade on its popular egg custard variety.

At Wang Bao He, a century-old restaurant known for its crab dishes, all 6,000 boxes of crayfish mooncakes had been preordered following a mid-July launch.

"I am taking calls every day, asking for more crayfish cakes. But my kitchen is already having a revolt to get the 6,000 boxes out," said Wang Hao, chef at the restaurant.

Each mooncake contains four freshly peeled crayfish, which are fried with garlic shoots and mushrooms before being stuffed into the pastry. Each box of 12 cakes sells for 180 yuan. Wang's kitchen can make a maximum of 200 boxes a day.

Outside the restaurant, scalpers have raised the price to 350 yuan a box, proclaiming that "the price is going up faster than Shanghai real estate".