I lived near a Scandinavian bakery when I was young. My mother brought home marzipan cakes from this bakery for several of my birthdays. They are one of my favorite things on Earth. This cake is a perfect substitute. I have to master making stabilized whip cream before I can make the marzipan cake. The texture of this cake is more course. But this cake gives me enough of one of my favorite experiences to make me very happy. The cooking time may be too long. Since I have to eat the cakes I make and since I cannot eat cake all the time without worrying about becoming too big, I cannot experiment by changing my ingredients or baking times at this moment. Use cake flour, baker’s sugar and a cake tester and shorten the baking time to prohibit the outside of the cake from becoming too tough. If you do not want to experiment to have a different texture, use all-purpose flour and granulated sugar. Serve the cake on a side of the cake if the outside of the cake is tough. The cake is amazing. Use jam from Switzerland, Europe, or jam from Stonewall Kitchen in America. I cannot currently identify this type of cake. The cake is leavened with baking powder and egg whites. The cake does not appear to be a sponge cake. The cake may be a light and fluffy scone. At Google the English translation for the Norwegian word bløtkake is the French word for cake, gateau or gâteau, which may traditionally be a type of sponge cake.