Step by step

Gently fold in the beaten egg whites, which should be firm

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.