Heat 1/8 litre milk, crumble yeast into it and dissolve. Put the flour in a bowl, press a depression in the middle, pour in the yeast milk, mix some flour with the milk and leave to rise in a warm place for about 15 minutes.
In the meantime, bring the remaining milk, 1 vanillin sugar, 125 g sugar and lemon peel to the boil, add the rice pudding and leave to swell for about 20 minutes while stirring. Stir cream and sauce powder until smooth.
Melt the fat. Add the egg, 50 g sugar, remaining vanillin sugar, salt and fat to the flour, work into a smooth dough with the dough hooks of the hand mixer and leave to rise covered in a warm place for approx. 30 minutes.
Let the rice pudding cool down in a mixing bowl, stirring from time to time. Stir the cream into the rice. Beat 3 egg whites until stiff and fold into the rice mixture. Roll out yeast dough on a greased fat pan, add rice and smooth it down.
Bake the cake in the preheated oven (electric: 200 °C / gas: level 3) for about 30 minutes. Beat the remaining egg white and sugar until stiff. 10 minutes before the end of the baking time, spread a thin layer of egg white on the cake and bake until the end.
Let the cake cool down and dust with icing sugar. Makes 36 pieces.