Chocolate and vanilla marble loaf cake

Ingredients

For the marble cake:
• 225g (8oz) unsalted butter, softened
• 225g (8oz) golden caster sugar
• 275g(10oz) self raising flour
• 2 teaspoons baking powder
• 4 eggs
• 2 tablespoons semi-skimmed milk
• 1/2 teaspoon vanilla extract
• 1 1/2 tablespoons cocoa powder
• 1 or 2 tablespoons warm water
For the icing:
• 2 tablespoons unsalted butter, melted
• 1 1/2 tablespoons cocoa powder
• 2 tablespoons semi-skimmed milk
• 100g (4oz) icing sugar
• 25g (1oz) white chocolate, melted

Directions

The marble cake:
1. Preheat the oven to 160°C/Fan 140°C/gas 3. Lightly grease a 900g loaf tin and line with a wide strip of non-stick baking parchment to go up the wide sides and over the base of the tin.
2. Beat the softened butter, sugar, flour, baking powder, eggs, milk and vanilla extract until well blended.
3. Transfer half of the cake mixture into another bowl and set aside. You will use this to make the chocolate cake mixture.
4. ix the cocoa powder and enough warm water (about one or two tablespoons) to create a smooth chocolate sauce. Stir this into one of the vanilla cake mixtures until evenly mixed.
5. Spoon the vanilla and chocolate cake mixtures into the lined loaf tin, alternating between the two mixtures until both portions are used up.
6. Bake for 50 minutes–1 hour, until the cake is well risen, springy to the touch and beginning to shrink away from the sides of the tin. Allow to cool in the tin for a few minutes, then turn out onto a wire rack, peel off the lining paper and leave to cool completely.
The icing:
7. Stir warm melted butter and cocoa powder together; add milk and icing sugar and continue to mix until evenly blended and slightly thickened.
8. Spread the chocolate icing over the top of the cooled cake and leave to set.
9. Drizzle the melted white chocolate over the top. Leave to set.