SEOUL - Chewy, crunchy and not-too-sweet, round, chocolatey "Dubai-style" cookies have become the must-have dessert in South Korea -- with the rush for the snacks even prompting the Red Cross to offer them as a draw for blood donors.
Springboarding off a global craze for "Dubai chocolate" -- a pistachio-filled chocolate bar layered with fine shredded pastry known as kadaif -- and fuelled by K-pop endorsements, "Dujjonku" have become a phenomenon in South Korea.
Online searches for the dessert surged more than twentyfold in the last three months, according to data from Naver, the country's largest search engine.
Searches on food delivery apps for the snacks jumped by 1,500 times last month.
And one developer even created an online map to track which shops still have stock remaining -- convenience store versions have also repeatedly sold out.
Customers have lined up outside shops in the early hours of the morning, even as temperatures have plunged in South Korea's bitter winter.
To make them, cafes melt marshmallows to create a chewy outer layer mixed with chocolate, then fill individual portions with pistachio cream and kadaif before dusting the top with cocoa powder.
They don't come cheap -- weighing at just 50 grams, the average price for the dessert currently stands at 6,500 won ($4.40).
Purchases are often limited to two per person, probably for the best given a single cookie can pack up to 500 calories.
That's sparked health warnings from experts, with Korea University Guro Hospital saying the dessert can "immediately disrupt the body's metabolic balance" and "threaten the overall health... beyond simple weight gain".
The craze is partly driven by celebrity endorsements from K-pop stars.
The trend appears to be spreading to neighbouring China as well, with the hashtag "dubaichocholate" drawing more than 329 million views on Instagram-like Xiaohongshu.
The craze has also sent prices of raw materials soaring.
A kilo of unshelled pistachios has surged fourfold month-on-month since mid-January.
And the price of 500 grams of kadaif has doubled, according to price-tracking app Fallcent.
The frenzy has spilled into unexpected areas.
Sushi and traditional Korean restaurants have begun making the desserts in a lucrative side hustle.