Cream butter with egg yolks and sugar, add sour cream, soda and flour. Knead the dough and bake three dough layers.

Steam and pit prunes, mince. Whisk butter with 4 tablespoons of sugar. Whisk sour cream with 4 tablespoons of sugar. Mix both masses, add nuts and prunes.

Interlay dough bases with prepared cream. Whisk whites with 4 tablespoons of sugar, brush the surface of the torte.