The dough mixed with butter is kneaded to form multiple layers; a bag of five pieces costs 20 yuan at Deda Restaurant.[Photo provided to China Daily]

Priced at 20 yuan ($3) for a bag of five pieces, the butterfly pastry has been flying off the shelves of two of Deda's outlets. Long queues are formed even before the pastry is unveiled to the public just after noon and the restaurant has been propelled back into the spotlight for the first time in decades.

This crispy and flaky puff that is lightly sprinkled with sugar crystals is believed to be a "crossbreed" of Chinese and Western culinary influences, first created in the 1930s. Unlike those found in Beijing, which are usually much smaller in size and harder in texture, the Shanghai version is extremely flaky and crumbs fall like snowflakes after a bite.

Having been in the pastry business for more than 40 years, Lin served his apprenticeship with Bian Xinghua, one of China's most famous pastry chefs who was awarded a gold medal at the 17th Culinary Olympics, held in 1988 in Germany. Lin remembered that Deda sold its first bag of butterfly pastry in the 1970s when China first opened up to the world.

Called Cosmopolitan Cafe when it was founded in 1897, Deda earned itself a reputation for being one of the city's best Western restaurants serving authentic German cuisine. It was renamed Deda, meaning "German feast" after the government took over the business in 1949.

Lin said that ingredients in the past were limited and often of mediocre quality, but customers were still easily satisfied with his products. These days, however, with the influx of foreign bakeries around the city and consumers' knowledge of the craft of making pastries, people are far harder to please.