Mix together all the ingredients for the dough, then add the flour and mix well. Dissolve the potash and deer horn salt in a little water beforehand.
Shape small dumplings with 2 teaspoons and place them in the middle of a wafer. Now place the cookies on a baking sheet and leave enough space between them.
Preheat the oven. Bake at about 200 ° C on the middle rack for about 5 - 7 minutes. Let the biscuits cool down (at least lukewarm).
Dissolve the coconut oil (preferably in the microwave) and stir in the sifted powdered sugar and cocoa with a whisk or fork until no lumps can be seen. Now apply the glaze to the cookies with a spoon and a brush.
It is best to let the whole thing cool down overnight with the window open. Quickly hide from the rest of the family the next morning.
All in all, you need about 1 hour with preparation, baking and glazing.