Preheat the oven at the top and bottom. Grease the mould.
Stir the soft margarine(or butter) with a hand mixer with whisk until it becomes smooth and homogenous.
Gradually add the sugar, vanillasugar, rum flavouring and salt, and stir until the mixture thickens.
Add 1 egg at a time, whisking each one for about 1/2 minute at the highest setting(very fast).
Mix together the flour and baking powder, sift and add to the margarine and egg mixture in 2 stages, alternating with the milk, stirring briefly with a mixer set at the medium setting.
Spoon two-third of the cake mixture into the greased tin(mould).
Sift the cocoa powder and add to the rest of the cake mixture together with the milk and sugar.
Spoon(put) the dark-coloured cake mixture on the top of the light-coloured cake mixture and drag a fork or spoon through the two layers in a spiral movement to create a marbled pattern.
Put the mould(tin) on a shelf in the oven.
On Top/bottom heat: 180ªC(350ªF)-preheated
Fan oven: 160ªC(325ªF)-not preheated
Baking Time:- about 60 minutes
Type of Mould:-
You need a ring shape(gugelhupf) mould of 24 cm(9 1/2 inches) diameter
or
A well greased rectangular tin(35*11 cm/ 14*4 1/2 inches).
Ater about 15 mins in the oven, make a cut about 1 cm in deep in the middle along the length of the cake to ensure a neat crack in the centre and continue baking.