butter, for greasing
4 large eggs
250g golden caster sugar
250ml sunflower oil
1 tsp vanilla extract
475g self-raising flour
1 tsp baking powder
25g cocoa powder
Preheat the oven to 180C/350F/Gas 4. Butter a cake tin.
Put the eggs and sugar into a large bowl with the milk, oil, vanilla extract and 175g of the flour. Whisk with a hand held electric whisk for a minute or two, until smooth.
Pour half of the mixture into a separate bowl and stir in ½ tsp baking powder and 175g flour and set aside. In the other bowl, mix the cocoa, 125g flour and ½ tsp baking powder.
Spoon two tablespoons of the plain mixture into the cake tin. Straight away spoon two tablespoons of the chocolate mixture on top. Continue doing this until all the mixture has been used – you will end up with lots of alternate rings of mixture in the tin. Don’t worry if it’s not very neat.
Cook for 40-50 minutes, until the cake is cooked through – a skewer inserted into the centre should come out clean. Turn the cake out onto a wire rack to cool before serving.