Place the yeast dough plates next to each other and allow to defrost. Then knead well with your hands. Cover and let rest at room temperature for about 15 minutes. In the meantime, finely chop the walnuts and pineapple.
Separate the egg. Mix walnuts, pineapple, honey, egg white and cocoa. Peel and core the apple and grate finely with a kitchen grater. Fold into the mixture. Roll out the dough to a rectangle (approx. 25 x 30 cm) on a lightly floured work surface.
Spread with the mixture and roll up. Cut the roll into about 12 equally sized triangular pieces. Place on a baking tray lined with baking paper and leave to rise in a warm place for about 45 minutes.
Mix egg yolk and condensed milk and brush the surface of the dough with it. Bake in the preheated oven (electric oven: 175 °C/ gas: level 2) for approx. 20 minutes. Let the bobbes cool down. Mix icing sugar and lemon juice and brush the bobbes with it.
Allow to dry. Arrange on a plate and decorate as desired with lemon balm. Makes about 15 pieces.