The first time I tried out this recipe I made a big boo-boo. I missed out on adding the baking powder and thought that the cake would turn out tasting really horrible. Surprisingly it did not. I even took it to the office and my colleagues liked it.
The second time I baked this again, I made sure I read the ingredients properly and ticked each one off as I assembled everything together. The recipe has a few more steps than most usual marble cakes but I have to say that it taste really good. I actually prefer it the day after as the oil from the butter seems to make the cake more moist and flavourful.
Recipe Adapted from Here
8 large eggs, separated
200g castor sugar
340g unsalted butter
255g all purpose flour
1 1/2 teaspoons baking powder
1 1/2 teaspoons pure vanilla extract
2 tablespoons good quality cocoa powder
1/4 teaspoon salt
1/2 tsp orange zest
1) Preheat oven at 180C (165C for convection fan) with a wire rack in the middle. Line an 8-inch round cake tin with parchment, butter and flour. Sift flour, baking powder and salt in a bowl. Set aside.
2) Cream butter in the bowl of a stand mixer fitted with the paddle attachment till light and fluffy.
3) In a separate bowl, whisk the egg yolks with the sugar till light. Gradually add this into the butter and beat on medium speed till just incorporated.
4) In a separate bowl, with a hand mixer, whisk the egg whites till stiff peaks form. With a spatula, fold in the meringue into the egg yolk mixture in 3-4 batches.
5) Add in the dry ingredients gradually until just incorporated. Divide the batter into two, 3/4 in one batch and the rest in another bowl. Add the orange zest into the larger batch. Then sieve cocoa powder over the lesser batch and fold to mix well.
6) Pour batter into tin, alternating between the two mixtures, starting with the yellow batter and ending with the cocoa mixture. Rap pan on counter several times to eliminate air bubbles.
7) With a long skewer, swirl around the batter to create the marble effect. Bake for 40-55 minutes or until a tester inserted into the middle of the cake come out clean.