Beat the butter with the salt and sugar until creamy.
Add the eggs and beat until combined.
Add grated carrots and mix together.
Combine baking powder, flour, vanilla, cinnamon, cardamom and ground almonds and add by tablespoonfuls to the carrot mixture and stir.
Stir in the apple vinegar, sultanas and walnuts.
Grease the springform pan a little and pour in the cake batter and smooth it out.
Bake the carrot cake in the oven for approx. 50 minutes. After 50 minutes, do the chopstick test. To do this, prick the cake with a knife or chopstick and pull it out again. If there is dough on the knife or stick, bake the cake for a few more minutes.
Remove the cake from the oven and leave to cool completely.
Casting
Sieve the icing sugar.
Mix all the ingredients for the icing together and spread over the cooled cake.