In a large bowl, cream the white sugar and butter until light and fluffy. Beat the eggs and add to the sugar mixture. Stir in the prunes.
In another bowl, sift the flour, bicarb soda, baking powder, cinnamon, nutmeg and salt. Add these dry ingredients alternately with the buttermilk to the sugar mixture.
Pour the batter into 2 greased and floured 23cm cake tins. Bake at 190 degrees C for about 30 minutes. Cool.
Begin by creaming the butter. Beat in the egg yolk. Sift the icing sugar, cocoa and cinnamon together. Add this sugar mixture alternately with the hot coffee to the creamed butter. Ice the cooled cake.