Hong Kong took a while to catch on to them, says Yu, who runs baking and party supply store Complete Deelite. Cupcakes are as American as apple pie, but they only became hip when a Sex and the City episode featured New York's Magnolia Bakery and 'made them a posh item', says Yu. But despite the popularity of the TV series in fashionable Hong Kong, many of the city's trendies lacked their American counterparts' tradition and nostalgia for the cakes.

Many Asian palates weren't used to such a sweet dessert, says former banker Lachlan Campbell, who last December opened Babycakes, Hong Kong's first specialist cupcake bakery. So, his company adjusted its recipes to potential customers' tastes.

And when Complete Deelite's customers asked for a lower frosting-to-cake ratio, the bakers introduced Rainbow Bright, a vanilla cupcake iced with a thin layer of buttercream. Such ingredient adjustments seem to have worked. Hong Kong Chinese customers make up 40 per cent of Babycakes' business, and about half the clientele for Complete Deelite, which claims a 10-fold increase in business over the past four years.

Dessert boutique Petits by Deschamps also changed the classic American cupcake by filling them with fresh fruit, jams and jellies, and topping them with lighter mousses rather than heavy buttercream.

Company director Lewis Ho Chi-ngon also broke away from cupcakes' standard vanilla and chocolate and embraced flavours such as lychee, Thai iced tea, kaya (coconut jam) and mango-ginger .

'We thought we should do something new to attract customers,' says Ho. 'Some people from the US complain that these are not real cupcakes, but more than 80 per cent of Petits' cupcake business comes from the new creations.'

Cupcakes are popular because they are so easy to eat.

'No forks, no knives and no plates - just peel off the paper and take a bite,' says Yu. 'Plus, there's something special about getting your own cupcake, and not a sliced-up piece of a larger cake.'

That makes them popular at children's gatherings and office parties, bakers say.

'Once one person catches onto the cupcake craze, they come back and buy a dozen more to share with their friends at work, and before you know it, the word-of-mouth news is spreading fast,' says Campbell.

They are even being used as a modern alternative to wedding cakes, even though the baking and decoration of lots of individual cakes takes longer than making a larger tiered cake.

'The designs look beautiful, but many of them are extremely labour-intensive,' says Charmaine Li Chi-yin of the new Pigasus Bakery.

She describes how she once painstakingly piped individual haystacks and roses out of buttercream for a barnyard-themed cupcake order. 'One of the most labour-intensive elements is piping details with buttercream,' she says, adding she has also piped the bride and groom's names on more than a hundred cupcakes for a wedding.

'You have to perfect the design on every cupcake so they look identical,' Li says. 'People may not pay attention to a cake once it's sliced up, but each cupcake is examined carefully.'

Cupcakes should be made from wholesome products, 'especially if they are being served to kids', says Li, who uses organic ingredients and free-range eggs. Babycakes says its allergy-conscious cupcakes are free of trans-fats and nuts, and use Callebaut chocolate and Nielsen-Massey Madagascar vanilla for a more sophisticated taste. The pastel pink cupcakes at Sift are made with strawberries in lieu of red food colouring, and Petits will launch a sugar-free, mini-sized cupcake later this year.

The supply of cupcakes is growing with demand in Hong Kong. Complete Deelite's cupcake trade has tripled since it opened, Yu says. In June, Petits will open a second branch at Hong Kong International Airport and Sift will open a patisserie at Horizon Plaza next to Babycakes, which plans to open a second store by the end of the year. Pigasus bakery also seeks outlets.

Still, some store-owners are hesitant about whether Hong Kong appetites can sustain the cupcake trend for long. 'At Magnolia in New York, they can sell 1,500 cupcakes a day. There are 20 more cupcake stores in Manhattan alone that all do well. I'm not sure Hong Kong can support the same amount of cupcake consumption for that many years,' says Sift chef Jennifer Cheung Hing-wai.

Ho, who says trends here come and go quickly, says that regularly changing Petits' cupcake flavours could be essential for the shop's longevity.

'A few years ago, you couldn't find a single cupcake anywhere in Hong Kong, but now they have most definitely arrived,' says Yu. She recently installed a new refrigerator to store Complete Deelite's growing inventory of cupcakes.

'It's only one new fridge,' she says. 'But I see it as one small step for us, and one giant leap for cupcakes.'