Cake: Preheat oven to 300°F/150°C/Gas mark 3.
Grease and line a 900g loaf tin.
Cream together the Unsalted Whirl and sugar until light and fluffy.
Gradually beat in the eggs.
Fold in the flour, then stir in the coconut milk and vanilla essence.
Divide the mixture into two bowls.
Stir the cocoa powder into one of the mixtures.
Then spoon in layers of each mixture on top of each other up to the brim of the tin.
Use a palette knife to even the top of the mixture, then take a skewer and lightly swirl to create the desired marble effect.
Cook in the oven for approx. 1 hour 15 minutes.
When the cake is cooked allow to cool and remove from the tin.
Topping: Gently heat the Unsalted Whirl and cocoa powder then stir for about one minute until blended.
Stir in the milk and icing sugar and then remove from the heat.
Allow to cool slightly and then evenly spread across the top of loaf.
Heat the white chocolate and drizzle across the top of the cake.
Dust with icing sugar to serve.