2) In a large bowl, sift together the flour, bicarbonate of soda and cocoa powder. Add the fennel, cardamom, salt and sugar and mix well to combine.
3) In another bowl, whisk together the water, vinegar and oil and then add to the dry ingredients. Mix well and pour into the prepared cake tin.
4) Bake for 1 hour. The cake is done when a cocktail stick comes out clean when inserted into the centre. Cool on a rack and dust the top with icing sugar before serving.