To make the cake

1. Pre-heat the oven to 180 degrees celsius and line a 2lb loaf pan with baking paper
2. In a large bowl mix together the flour, cornflour, baking powder, bicarbonate of soda, salt and sugar
3. In a separate bowl mix the wet ingredients together, this makes the vanilla batter.
4. Add the wet ingredients to the dry and mix to combine
5. Put half the mixture into another bowl and add the cocoa powder and extra milk to make the chocolate batter.
6. A few spoons at a time, alternately add both batters to the loaf tin, so a blob of vanilla, a blob of chocolate, a blob of vanilla etc.
7. Once the loaf pan is full, use a skewer to gently swirl around the batter
8. Cook in the oven for 50 minutes or until a skewer comes out clean
9. Leave the cake to cool in the tin until it is cool enough to ice

To make the icing

1. Chop and melt the dark chocolate and add the non dairy milk until it is the desired consistency
2. Pour the icing over the cool cake and sprinkle with the chopped nuts.