This recipe was in the original EDC but not in the latest 2013 version of the book. So here it is for those who don't have the old EDC.
300g butter, softened
270g sugar/split
1 tsp vanilla sugar/essence
Few drops rum essence or rum
pinch salt
5 eggs
370g self raising flour
70g milk/split
1 tbspn cocoa powder
Pre-heat oven to
180oC.Place butter into TM bowl and mix for
1 min/speed 5.
Add
250g of the sugar, vanilla, rum, salt and mix to combine for
45 sec/speed 5.
Add eggs one by one through the opening in the lid and mix for
approx 15 sec/speed 5.
Add flour,
40g milk and blend for
20 sec/speed 5.
Place
2/3 of the mixture into a well-greased large flute tin.
Add the cocoa powder, remaining 20g sugar and remaining 30g milk to the rest of the mixture and mix for
5-10 sec/speed 5.
Place the dark mixture over the light one and slightly swirl with a fork to create a marble pattern or as Sue purrb suggests to ensure it marbles all the way through to the bottom, place alternate spoonsful of the light and dark mix around the cake pan, layering it until all the mix is used up, then swirl with a skewer.
Bake in a moderate pre-heated oven for approx.
30-40 mins or until golden brown and a skewer comes out clean.
Dust with icing sugar to serve.
Review of the original recipe
here