Step by step

Then add milk and yoghurt and work the mixture a bit more

Tips
The dough base of this recipe lends itself to being adapted according to taste or opportunity: you can substitute apples or pears for plums, or add a few drops of chocolate or coffee.
Trivia
In English ‘plum cake’ is most likely to refer to a dessert of German origin, whilst in Italy the plum cake is instead a leavened cake usually rectangular in shape with fruit and raisins or chocolate.