Gone marbles cake

Method

• 1
  Preheat oven to 160C and grease a 23cm cakepan.
• 2
  For the marble cake, in an electric stand mixer with beater attachment, beat sugar and butter until softened and slightly lightened. Slowly add egg whites, then add plain flour, baking powder, cornflour and almond meal. Add crème fraîche and cream, and mix to combine. Lastly, add the juices and zests, and continue mixing for 30 seconds, until well combined. Divide mixture evenly among 6 bowls (230g each), and use food colourings to make each a different colour, stirring the colour through with a spoon.
• 3
  Add coloured cake batters to the prepared pan in a random mix to form a marble effect. Bake for 60-80 minutes or until the centre is cooked and stable. Remove from oven and leave to cool in the pan for 15 minutes before turning out onto a wire rack to cool completely.
• 4
  Meanwhile, for the ganache, place dark chocolate in a food processor and blitz to make small pieces. In a saucepan, place the cream, butter and glucose and heat to 65°C on a cook’s thermometer. Pour the hot mixture over the chocolate in the food processor and blitz until smooth and glossy. Pour into a container and cover with plastic wrap, without touching the surface of the ganache. Place in a cool space to set at room temperature.
• 5
  To assemble, use a serrated knife to trim the top off the marble cake (it will have formed a slight peak which may have cracked open), to make an even-sized cake. Cut the cake horizontally through the middle and separate the halves. Place some of the ganache on the bottom layer – enough to give roughly an 8mm layer – and use a palette knife or spatula to spread evenly. Place the top cake layer on, and cover with more ganache using the palette knife or spatula. Make the entire cake as smooth and neat as you can, covering the whole cake with ganache, then set aside.
• 6
  For the decoration, for the initiated, spread some tempered chocolate, milk or dark, onto a marble top or a cold tray and leave to ‘just’ set. Using a palette knife, gently cut through while pulling down to form chocolate curls. Arrange the curls to your liking on top of the cake and serve. If you don’t know how to temper chocolate, you can make chocolate curls using a vegetable peeler and a block of good-quality, store-bought chocolate. At a pinch, you can grate the chocolate as an alternative decoration.