Sift 200 g flour into a bowl, add the egg, butter and sugar and knead everything. Dissolve the deer horn salt in a little hot water, pour it hot over the dough and knead the remaining flour with it.
Roll out the dough to a thickness of approx. 4 mm and cut out cookies with a wine glass. On a sugar-sprinkled board, roll these out gently with a rolling pin into tongues. Place with the sugar side up on a baking sheet lined with baking paper and bake at 175 degrees until the sole has risen, but must not turn brown.
Now the buttercream (possibly according to your own recipe), I make it with pudding and butter, prepare and brush one sole with it, put a second sole on top and press it down lightly.
These cakes only taste particularly good the next day, beautifully drawn and juicy.