Traditional German Plum Cake (Zwetschgenkuchen) - cooking recipe

Ingredients

Dough
4 cups all-purpose wheat flour
1 ounce baker's yeast, see note
4 tablespoons sugar
1 cup milk
1/3 cup butter, unsalted and melted
1 egg
1 pinch salt
Filling
3 1/2 lbs damson plums, see note
Topping
4 tablespoons sugar
1 teaspoon ground cinnamon

Preparation

Sift flour into a large bowl and make a well in the middle.
Crumble yeast into well and mix it with 1 tablespoon of sugar, milk and some flour. This first yeast-mixture should be still fluid. Cover and let rise in warm place for 20 minutes.
Add remaining sugar, melted butter, egg and a good pinch of salt and mix with yeast mixture and flour. Knead with floured hands until dough is peeling away from the side of the bowl and blistering. This step may take 10 minutes (or more). Use some additional flour, if dough is too sticky. At the end you should have a smooth dough.
Cover and let rise in warm place for about 25 to 30 minutes or until dough has doubled.
Meanwhile prepare the plums. Cut lengthwise and pit them. Cut the still connected plum halves once again lengthwise, but do not cut through. You should have a depitted plum which you can easily flatten.
Grease backing tray. Dough is calculated for a baking tray of 11 3/4 x 15 inches.
Remove yeast dough from bowl, knead once or twice and roll out on baking tray using a floured rolling pin. Along the sides of the baking tray form a border with yeast dough.
Place plums on yeast dough in closely rows and press slightly into dough. Let rise again for 15 minutes.
Preheat oven (425 F, 220 C).
Bake the plum cake in the middle of the oven for 20 to 25 minutes.
Meanwhile mix sugar and ground cinnamon for topping.
Remove plum cake from oven and sprinkle with sugar-cinnamon mixture. Cut into 20 pieces and serve warm or cold with whipped cream.
NOTE on Baker's yeast: If possible use fresh baker's yeast. But you can replace it by 1 1/2 packages dry yeast.
NOTE on Damson Plums: a traditional German Plum Cake is made with the slightly tart and not too juicy Damson Plums. You can also use other plum varieties, but the plums shouldn't be over-ripped or too juicy. I have tried it with other plum varieties and have reduced amount of sugar in topping.
NOTE on traditional German Plum Cake: in my opinion this cake has to be made with yeast dough. It takes more time to make than other doughs, but it is worthwhile. Don't be afraid of the juices. This cake has to be juicy!
There are existing several names for this type of frutit cake in Germany: Zwetschgenkuchen, Pflaumenkuchen and in Bavaria Zwetschgendatschi. Zwetschgen is the German name for Damson plums.