I was born and raised in Germany, and I have many good memories about my mother baking every Sunday and holiday. It's on these memories that I rely, as well as her trusted cookbook from 1958, when it comes to reminiscing about traditional German desserts and pastries.
Blachkuchen (sheet cake):
The base for this cake is sweet, yeasty dough. Not an easy feat to manage before the time of dough hooks and bread machines! This dough is pressed onto a large sheet (almost as large as the oven space) that has a rim about one inch high.
There are many toppings and fillings that can go on top. My favorite was Mohnkuchen. Mohnkuchen is made with a poppy seed filling. My mother ground the poppy seeds in a manually operated coffee grinder. Actually, come to think of it, when I was old enough this task fell to me.
The ground poppy seeds were cooked in milk with raisins. This filling was then spread over the dough, and topped with Streusel. Streusel is a crumb mixture made with (unsalted) butter, flour, and sugar. Streusel can also be used to make Streuselkuchen. This simply means that the Streusel gets put on top of the dough base by itself (without any filling) and baked like that.
Some other types of Blechkuchen are the ones topped with fruit, such as Apfelkuchen (apple cake) and Zwetschgenkuchen (plum cake). The same concept applies as with the Mohnkuchen. Once the fruit tops the dough base, Streusel finishes it off, and then the cakes get put into the oven.
Another popular type of Blechkuchen is Zimtkuchen (cinnamon cake). In this case, the dough base gets dotted with (unsalted) butter, and topped with a sugar and cinnamon mixture, then baked. Another variety of this type of cake is Rahmkuchen. The same steps apply as to the cinnamon cake, but a sour cream (Rahm) mixture is put on top of the sugar and cinnamon mixture, and then baked.
Traditional German cheesecake does not have a graham cracker crust, but a base made with flour, egg, sugar and butter, baked in a round spring form. The traditional filling is made with Quark (loosely translates to curd), Saure Sahne (sour cream), eggs, and sugar. Unlike other country's traditions, it is not customary to top Kasekuchen with fruit in Germany.
Kuchen is simple, every-day cake, the type you would find on the grocery store shelf. Of course traditionally it's made from scratch with butter, sugar, eggs, and flour, baked in a square pan. For variety, this cake is made with different flavorings, such as cinnamon or vanilla, and glazed with icing. This icing, unlike American frosting, is not made with butter. It's simply made with powdered sugar and liquid. The type of liquid used determines also the flavor of the cake. For example: lemon juice for lemon cake, orange juice for orange cake, or red wine for red wine cake. To make chocolate icing, baking cocoa gets mixed in with the powdered sugar and the liquid used is water, with a bit of vanilla added.
Torte is a round, layered cake with a creamy filling in the middle. A good example of this is (authentic) black forest cake (Schwarzwalder Kirschtorte). Don't be fooled by the imitation recipes for this German classic. The real thing is made with a dark biscuit base (flavored with cocoa or chocolate), and two layers of regular cake. The bottom layer usually gets filled with cherry preserves flavored with cherry liqueur. The filling is pudding based, and the topping is whipped cream.
The pudding fillings mentioned above are the most popular kind for different types of Torte, such as chocolate. Preparing pudding with boiled milk makes this type of filling. The pudding gets cooled down to room temperature, and added to creamed butter. This is a tricky part. The temperature of the butter has to be close to the temperature of the pudding, or something nasty called "Gerinnung" will happen. It does not look very appetizing when that happens (think curdled milk).
Different flavors of pudding are used to make different types of Torte. Chocolate, vanilla, lemon and butterscotch are some popular examples.
Marzipan can be best translated as almond paste. This confection is popular around Christmas time. The traditional way of making marzipan is with finely ground almonds, rosewater, and powdered sugar. A lot of Internet recipes will tell you to make it with egg white, but that is a misconception. Marzipan can be shaped into balls and rolled in cocoa powder for an easy treat. The store-bought kind is usually shaped into loaves or animals (pigs are popular). The loaf type is coated with chocolate.
Stollen is a typical German Christmas item. It's a loaf made with a sweet yeasty dough that contains raisins, nuts, orange peel, and sometimes marzipan. It is coated in powdered sugar. You may have seen Stollen even at your local grocery store, as it has become quite popular for the holiday season.
Krappel can be translated to doughnuts, but I have never had a doughnut yet that tastes anything like the ones my mother made. Usually she made them for New Years only. Possibly because they are time consuming to make. The dough is made with yeast and has to get kneaded. Then it has to rise. Then it has to get kneaded again. Then it has to rise again. I can't remember how often this step gets repeated, but the whole process of making these took all day.
Once the dough was done rising for the final time, it was rolled out with a rolling pin. We used a simple drinking glass upside down (dipped into flour) as a cookie cutter to make circular shapes. Then we put a teaspoon of homemade strawberry preserve into the center of half of the circles. Then we took the remaining dough circles and put them on top of the ones with the filling. After that we used a slightly smaller drinking glass and pressed it upside down to cut out the final Krappel (or doughnut shape). What's the next step? You guessed it - they had to be set aside to rise again, under kitchen towels in a warm place. To finish, we deep-fried them in hot oil.
So, where are the German chocolate cake and the Strudel? There is nothing German about German chocolate cake and Strudel is really from Austria, although Strudel is popular in the Southern regions of Germany, like Bavaria.