Mix flour, sugar and salt. Heat the fat and add milk. Dissolve yeast and add to the flour. Knead to a smooth dough with the dough hooks of the hand mixer. Cover and leave to rise in a warm place for about 30 minutes.
In the meantime, wash, halve and stone the plums. Knead the dough again and roll out on a baking tray (42 x 37 cm) lined with baking paper. Spread the plums on top and press them lightly into the dough.
Let it go again for about 30 minutes. Bake in the preheated oven (electric cooker: 200 °C/level 3) for 35-40 minutes. Beat egg white and lemon juice until very stiff, slowly adding sugar.
Pour into a piping bag with star-shaped spout. Divide the cake into about 20 pieces, sprinkle each piece with the meringue and bake under the preheated grill for 3-4 minutes until golden brown. Makes approx. 20 pieces.