See how tree cake is made at Racine Bakery in Chicago and watch this video of tree cake being made before an open fire in Lithuania.
In Poland, tree cake is known as sękacz (SAYN-kahch) or senkacz, which loosely translated means "bark." And in very politically incorrect terminology, it's also known in Poland as "beggar's cake" supposedly from the days when gypsies stole eggs and made them into a cake because it was more portable on the run than eggs in the shell.
In Lithuania, it's known as raguolis (which means "spiked") or sakotis (which means "branched"). In Hungary, they're known as kurtoskalacs or tepsiben, which means "little chimney cakes" or "stove cakes." In Germany, it is called baumkuchen, which literally means "tree cake." The final appearance and taste of the German cake are a little different from the Polish and Lithuanian versions, which are virtually indistinguishable -- pyramid-shaped with spiky ends. The technique, however, is the same -- pouring successive layers of batter along the length of a rotating wooden pole or stainless-steel rod in front of a heat source. When the hollow cake is cut, it reveals rings similar to a tree trunk, hence its name.
The Hungarian version -- kurtoskalacs -- is often served at traditional weddings, but it's very different from the Polish, Lithuanian and German versions. It is made with a yeast dough that is rolled and cut into strips and then wrapped around tubes (originally it was rolled on a log and turned on a spit over an open fire). Today's version can be made in a home oven on stainless-steel baking tubes that stand verticallyry. Originally from Transylvania, it is famous as Hungary's oldest pastry. Kurtoskalács is sold in bakeries, festivals and fairs, and on street corners. View this video of Hungarian chimney cake making.
I'm not aware of tree cake existing in other European countries, but it certainly may. As to its origins, it's the same old song and dance -- Poles say it began there, Lithuanians say they are the creators, and Germans claim it as their own.
This much is known about its Polish connections. Cukierna Zaniewicz, a bakery in Poland that specializes in making sekacz, says the cake originated in eastern Poland (near Lithuania, by the way!), but is now made by them in Miedzyrzec Podlaski in southern Poland.
The company continues to say on its website that legend has it five centuries or so ago, Queen Bona challenged the royal bakers to come up with an exceptional cake for the wedding of her son Prince Sigmund August, and sekacz was born. Such a laborious and expensive effort (five or more hours of patient ladling of an egg-rich batter over a rod that was hand cranked) could only be afforded by the nobility, so, naturally, it became coveted by the common folk and a trend ensued.
To this day, tree cakes are popular on sweets tables at Polish and Lithuanian weddings and for special occasions like Easter, Christmas and birthdays. They are often adorned with fresh flowers and herbs in the hollow top and at the base. Slices are cut off from the top horizontally and then further divided into bite-size pieces. In a concession to modern times, the pieces are often accompanied by fruit and melted chocolate, and presented very elaborately.