The Ljubljana štrukelj, a yeast-leavened laminated dough pastry filled with orange filling, apricot jam, vanilla and almonds, was given a modern twist 155 years after the recipe for the dish first came out in a book.

The oldest recipe for the Ljubljana variant of an Austro-Hungarian cake appeared in the first original Slovenian cook book Slovenska Kuharica in 1868.

Modernised by confectioners at the Biotechnical Educational Centre Ljubljana, the pastry was launched on 7 June at Be Trendy cafe in a new park just below Golovec hill.

The new variant differs from the original in the form of the cake, which being baked in individual round-shaped cake tins, comes out shaped like a rose.

To keep the cake authentic confectioners Stela Špoljar and Francka Mršnik preserved the original ingredients, but modernised it by slightly changing the amounts and the method of preparation.

They upgraded the recipe by adding home-made vanilla cream laced with orange and toasted the almonds for more flavour. They made the orange sugar crust crunchy and for a final touch added an orange chocolate ganache.

Conceived by Magdalena Knafelj Pleiweis, the original recipe is an important part of Slovenian cultural heritage and the capital's gastronomy. The initiative to revive it involved the well-known ethnologist Janez Bogataj.

In Slovenian štruklji denotes a rolled pastry dish usually made of leavened or rolled strudel dough and filings such as cottage cheese, walnuts or tarragon. They are as a rule cooked rather than baked and can be eaten as a sweet or a savoury side or main dish.

However, the Ljubljana štrukelj is different in that it is made of leavened laminated dough, is baked and having its own particular filling.

It is a variant of the Austro-Hungarian cake known as the wasp's nest or Ferdinand doughnut.

The cake is popular in the Danube region cuisine, but since the Slovenian variant uses slightly different ingredients, it was given its own geographical designation in one of the first such in Europe.

In the 19th century, the Ljubljana štrukelj was enjoyed mainly in urban areas on special occasions and did not spread to the countryside until after the Second World War.

The pastry did not earn the name Ljubljana štrukelj until 1912, when the first original Slovenian cookbook was reprinted for the sixth time.