And then on Great British Bake Off (there are some very English things I just can't give up) last night, that's what they made! It's official name is now Princess Cake. So I now even know how to make it (although I'm not sure I'm brave enough)
It is actually a traditional Swedish layer cake (Prinsesstårta in Swedish) but the Swiss have certainly adopted it because it is so scrummy. It consists of alternating layers of airy sponge cake, custard or raspberry/ strawberry jam (depending on whether you're a purist or not) pastry cream, and a thick domed layer of whipped cream. It is topped with lime green marzipan, in a perfect dome shape and sprinkled with icing sugar, and often decorated with a pink marzipan rose (the Swiss have dropped the rose too)
The recipe first appeared in the 1930s 'Prinsessornas Kokbok' cookbook, which was published by Jenny Åkerström, a teacher of the three daughters of H.R.H. Prince Carl, Duke of Västergötland. The cake was originally called "Grön tårta" (green cake), but was given the name "prinsesstårta" or "princess cake" because the princesses, H.R.H. Princess Margaretha (1899–1977; later Princess of Denmark), H.R.H. Princess Märtha (1901–1954; later Crown Princess of Norway), and H.R.H. Princess Astrid (1905–1935; later Queen of the Belgians) were said to have been especially fond it.
The cake is widely featured in Tom McNeal's book Far Far Away.