Take a mixing bowl (or the bowl of your food processor) and whisk together the soft butter, sugar and vanilla sugar. Use an electric whisk to obtain a light and creamy texture.
Add the flour in several batches, then the almond powder, half the grated coconut and the egg. Mix well until you get a nice homogeneous dough.
Preheat your oven to 180°C.
With your hands, form small balls of dough. Place them on a baking sheet lined with parchment paper, leaving a little space between each ball (they rise slightly during baking).
Bake for about 15 minutes. Watch the colour of the biscuits carefully: they should be lightly golden.
As soon as they come out of the oven, roll your still-warm biscuits in the remaining grated coconut for a perfect finish.