- 175g butter, softened
- 175g golden caster sugar
- 175g self-raising flour
- 3 large eggs
- grated zest from 1 orange
- 2tbsp orange juice
- 2tbsp cocoa powder
- Preheat the oven to 180°C (350°F/ Gas 4).
- Grease and line the base of a 20cm (8in) square cake tin with baking paper.
- Place all the ingredients except the cocoa powder in a large mixing bowl.
- Using an electric or hand whisk, beat them all together until mixed and smooth.
- Divide the mixture in half.
- Place large spoonfuls of one half of the mixture into the tin in each of the 4 corners and between each spoonful.
- Sift the cocoa powder over the remaining mixture in the bowl and whisk together until combined.
- Spoon the chocolate mixture into the spaces in the cake tin.
- Gently drag a round-bladed knife through the mixtures to create a swirl effect With the brown and white mixtures. Don’t over-do it, or you will make the two colours together completely.
- Bake a cake for 30 minutes, until well risen and springy. Allow it to cool in the tin, then remove it and perl off the baking paper. Cut it’s into 25 squares of a sharp knife.