Knead the flour, egg yolk, butter, sugar, vanilla sugar, chocolate flakes and cappuccino powder well. Wrap the dough in foil and let it rest for 1 hour in the refrigerator.
Roll out the dough on a floured work surface, cut out hearts, place on a baking sheet lined with baking paper and bake at 180 ° for about 12 minutes (convection 160 °). Let the hearts cool down.
Melt the chocolate icing and dip the hearts halfway in the icing and decorate with the mocha beans.