For the dough, stir the fat until foamy and gradually add the sifted powdered sugar, vanilla sugar, orange peel and spices. Mix in 2/3 of the flour mixed with cornstarch and baking powder, tablespoon at a time. Knead in the rest of the flour. If the dough sticks, refrigerate for a while.
Shape the dough into rolls with a diameter of approx. 2.5 cm. Cut about 0.5 cm thick slices, place a mocha bean on each slice, pour the dough over it, shape into balls and place on a baking sheet that has been greased or lined with baking paper. Preheat the oven (gas: level 2 - 3, convection: 175 - 180 degrees, top / bottom heat: 200 degrees) and bake the biscuits for about 15 minutes.
Stir together the ingredients for the topping until you have a smooth mass. Brush the curved side of the biscuits with the icing and sprinkle with granulated sugar.