shared by Doris Mok (Baking Corner member)
60g Butter melted on a double boiler with 110g heavy cream and cooled
6 yolks (large eggs)
110g cake flour
3/4 tsp baking powder
110g sugar (I used icing sugar)
1/2 tsp cream of tartar
Beat the yolks lightly before adding to the melted butter/cream. Then add the sifted cake flour/baking powder and mix till combined. Set aside.
Beat the egg whites until foamy before adding the cream of tartar. Beat until foam became more fine before adding the sugar and continue beating until stiff peaks. Fold in third portions into the yolk batter.
Take out about 1/2 cup of batter and mix with 1 tsp of cocoa powder. Pour half the plain batter into a 23 inch tube pan, add dollops of the cocoa batter and pour the remaining plain batter to cover the cocoa batter. Run a chopstick around the pan to create a marbling effect. Even out the surface before baking it for 50-55 minutes at 150C until golden brown.
Invert immediately to cool. Remove from pan and slice to serve.