* Tania Branigan in Beijing
* TheGuardian, Thursday 27 September 2012 11.04 BST
Freshly baked handmade mooncakes inPinagyao in northChina'sShanxiprovince – youngpeople increasingly prefer modern versions, such as those made by Häagen-Dazs.Photograph: Zhan Yan/Xinhua Press/Corbis
They widen waistlines, lighten wallets and even spread anti-Japanese sentiments. Tocritics, their yearly appearance is associated with waste and ostentation.
But China's centuries-long love affair with the mooncake is unstoppable. Eaten to celebratethe mid-autumn festival, when friends gather to admire the harvest moon, they have evolved, with the country's embrace of consumerism, to reach new heightsof luxury and exoticism.
"It's just like how Americans eat turkey. Nobody knows why we eat them, we just do," said 25-year-old Tang Cong, who works for an internet company in Beijing.
Roundor square, the palm-sized pastries – sometimes chewy, sometimes flaky – are decorated with patterns and traditionally filled with pastes such as lotus seed and sometimes salted duck egg yolks. As high in fat and sugar as they are richin flavour, they are usually eaten in small wedges, accompanied by tea.
Their increasingly esoteric fillings now include ham and rose petal, sea cucumber and peacock. Häagen-Dazs makes ice cream versions; Starbucks offers chocolate varieties. At the Chongqing Mooncake festival, the centrepiece is a 300kg monster.
They have even appeared in non-edible form. Gold shops sell solid discs styled toresemble the pastries. Last autumn, the makers of Angry Birds produced aspecial edition of the game with golden mooncake slices instead of eggs.