Fu Celiang mixes some glutinous rice with beach sand and stirs them in a big bowl.

"The beach sand helps make the temperature even and allows the baked rice to have lasting aroma," Fu said.

Fu, 46, is busy making Tanggong, a traditional sweet snack in Wenchang, south China's Hainan Province. For the traditional Lunar New Year, demand for Tanggong is soaring, Fu said.

"The snacks are a must-have for the Spring Festival," he said.

Tanggong, or rice flour sugar cakes, is a local snack that has enjoyed popularity in Wenchang for a long time. The Chinese name Tanggong means sugar for the imperial court, as it was served as an article of tribute to the imperial court in old times.

As the Lunar New Year approaches, every family is busy making Tanggong in Fu's home village of Fenghui, with a population of a little over 1,400.

"The aroma smells like happiness for many people," Fu said.

The village is famous for its Tanggong snacks, and the craft has been passed on for generations there. Fu learned the technique from his mother, and he has been making these sugar cakes for more than a decade.

"The main ingredients are glutinous rice, peanuts, sesame, and white sugar," he said. "The glutinous rice is important. Our ancestors started growing the rice from an early age, and each family has the seeds."

The process is quite complicated. After cooking the rice with beach sand, Fu uses the sand to cook peanuts before stir-frying sesame. He then melts the white sugar to make it sticky before mixing all the ingredients.

"Then we put the mixture into a wood mold, press it flat, and leave it to solidify naturally," he said. "The last step is to cut the entire piece into small ones, and that's how you get the sugar cakes."

Fu said his family used to make Tanggong for relatives and friends or send them to close relatives living far.

"In the past, many people would come to our village to buy Tanggong, but we only made a small amount, which was barely enough," he said.

In 2006, Fu started investing in a plant to make Tanggong. The business proved to be quite good, and Fu has reaped a good harvest over the last few years.

"We have a lot of orders for the Tanggong for this Spring Festival," he said, adding that more than 80 employees are currently working to meet the demand.

"Our sales revenue was more than 1 million yuan (about 157,200 U.S. dollars) last year. Supply is dwarfed by demand these days."

As China's logistics system improves, the snacks have reached areas across China through online sales.

"The sugar cakes have truly sweetened our lives," Fu said.