Like a tsunami that arrives without any warning, the confection known as "trilece" -- a sponge cake soaked in a creamy milk bath -- has taken Istanbul's dessert scene by storm over the last few years. From ritzy uptown patisseries to humble old city kofte joints, the dessert seems to be everywhere.

But where did it come from? That's the difficult question Culinary Backstreets tries to answer in a story posted today. Trilece (pronounced "tree-leche"), as the name implies, is connected to the famous Latin American tres leches cake. But the one that has taken over Istanbul hails from the Balkans, creating something of a mystery about how a cake with South American roots worked its way through the Balkans and into the pastry shops of Istanbul. From Culinary Backstreets' story:

We’ve been following the movement of trileçe all over the city and it is spreading fast. Just in the past couple of years, it has made its debut in sweetshops, from modern Etiler all the way down to the historic Grand Bazaar. There are wholesalers of this cake supplying restaurants all over town. Tuğra Restaurant, at the Çırağan Palace Kempinski hotel on the Bosphorus, includes it on the menu as a signature dish. But even more significantly, trileçe has breached the seemingly impenetrable bulwark against fads, working its way into even Köfteci Arnavut, a third-generation, exceedingly old-school meatball shop where the menu has not changed since 1947.

In this setting of fierce competition, it is no wonder that trileçe makers are hesitant to share their recipe. At Köfteci Arnavut they claim to mix kaymak, the heavy cream of water buffalo milk, and cow’s milk together for the characteristic soak given to the cake. At Baltepe Pastanesi, Idris Beğiroğlu called his recipe a secret but admitted that there was plenty of krem şanti, whipping cream, in there. Tuğra’s menu lists it as a cake of three milks – cow’s, goat’s and sheep’s. Istanbul, a city where condensed milk is not readily available, has adapted its own recipes, among which there is no real consensus. Yet still they all estimate the same desired effect.

After tasting trileçe all over Istanbul, we have the same recurring vision of someone accidentally knocking an extra-large Thai iced coffee all over a slice of vanilla birthday cake. We love cake and Thai iced coffee on their own, but a bite of trileçe squarely hits a spot for us that Turkish desserts rarely even tickle. Depending on the baker and his preference for normal flour or semolina, the cake is either more fluffy or crumbly, but that hallmark cloying effect of the cream and that ultra-sweet caramel topping are the common points which all trileçe conform to.

In our search for Istanbul’s trileçe roots, a tip on Twitter led us to Baltepe Pastanesi, near the weekly Fatih bazaar. This small corner shop, with its handsome old cooler and list of traditional desserts on the wall, had the innocent feel of a neighborhood hangout, like Arnold’s in Happy Days. A young couple at the next table shared a rice pudding.

The full article, with addresses of Istanbul's best trilece spots, can be found here.