If you made the Wartime Christmas Cake here is a recipe from 1942 to cover it with “marzipan”, note the use of our old friend the potato. No real icing, sugar was rationed.
Wartime Marzipan Paste
4 tablespoons mashed potato
1 teaspoon white of egg
1 tablespoon sugar
Few drops of almond essence
Mix all ingredients well together. Spread top of cake while still hot with honey or a little blackberry jelly, press marzipan out to size of cake, put on top and press into shape. Pinch up round the edges and score with a fork.
Put back into oven and brown up. While still hot sprinkle a circle of grated chocolate in the centre.