Sift the flours, baking powder, baking soda, salt and spices together into a bowl. Add the sugar, grated carrots, raisins and walnuts and mix everything so that the carrot, walnuts and raisins are well coated with flour.
In another bowl, lightly whisk together the milk or soya milk with the vinegar. To this add the vanilla and the oil. Make a well in middle of the dry ingredients and pour the whisked liquid ingredients into this. Gently stir till combined. Do not over-mix.
Scrape the cake batter into a lined and well-greased 8" cake tin and bake at 190C for between 1 and 1 1/2 hours. If the top of the cake is browning too much, cover the cake with aluminium foil half way through the baking.
When the cake is done (an inserted skewer/ knife should come out clean), take it out and leave it in the tin for about 20 minutes. Then remove and let it cool on a rack.
Once the cake has completely cooled, prepare the ganache.
Chop the chocolate and put into a bowl. Add the butter to it. Heat the cream, stirring constantly, over medium heat until you can see the steam rising from the cream. Pour the cream over the chocolate. Keep stirring the chocolate and cream together until the chocolate dissolves completely and ganache is smooth. If you feel the ganache is becoming thick, just place the bowl over simmering water and stir it. The ganache will thin, but be careful not to get any moisture into it.
Now pour the ganache over the cake and decorate as you wish. I used candied chocolate covered cashewnuts and candied carrot curls. This recipe makes one 8" cake.