Mix all dry ingredients and add the cold, chopped butter. As for a shortcrust pastry, quickly incorporate.
Refrigerate for at least 1 hour.
Arrange balls the size of small walnuts on top and chill again before baking.
Bake at medium heat (possibly convection oven 160 °C) for 10 to 12 minutes.
Tip: Use better chocolate – the better the result will taste!