Marble Cake

160g eggs (appr. 3 nos.)
150g castor sugar
180g butter/margarine
70g plain flour
80g self-raising flour
1.5 tsp baking powder
1/8 tsp cream of tartar
pinch of salt
2 tbsp cocoa powder

• Sift flour, salt & baking powder
• Beat butter/margarine until soft (about 2 mins)
• Add in sugar, beat until light & fluffy (about 3 mins)
• Add in egg yolks, one at a time
• Add in flour (low speed mixer)
• Beat egg whites in another bowl until foamy, add in cream of tartar, continue to beat till stiff
• Fold in the egg whites into the flour mixture, do not overmix
• Divide mixture into half
• Stir in cocoa powder into one half (chocolate mixture)
  
• Dollop the chocolate mixture and plain mixture into cake tin alternately until mixture is used up
  
• Ensure the base is evenly covered
• Use a skewer to swirl around the mixture a few times to make the marble effect
• Bake 150 C, 45 mins