225g butter, softened, plus extra for greasing
Finely grated zest of 1 orange
225g golden caster sugar
4 medium free-range eggs
200g self-raising flour
25g cocoa powder
For the decoration
2-3 tbsp icing sugar, sifted
4 tbsp orange juice (or juice of
100g milk or plain chocolate
Sugared orange sweets, such as Supercook Orange and Lemon Slices, from Sainsburys
Preheat the oven to 180°C/fan160°C/gas 4.
Rub a little butter inside a deep, loose-bottomed, 20cm square tin. Line the bottom of the tin with a piece of baking paper.
Put the butter into a bowl with the orange zest and sugar, and beat using a wooden spoon until really pale and fluffy.
Crack the eggs into a bowl and whisk with a fork.
Gradually add the eggs to the butter mixture, beating well after each addition.
Sift the flour and cocoa over the butter mixture and carefully fold in with a metal spoon.
Spoon the mixture into the tin, level the surface and bake for about 50 minutes-1 hour, until well risen and firm to the touch.
Leave the cake to cool in the tin for 10 minutes.
Poke holes all over the top of the partially cooled cake with a skewer.
Put the icing sugar and orange juice in a bowl and mix together, then spoon all over the cake. Remove the cake from the tin and cool on its lining on a wire rack.
Break the chocolate into pieces, put into a bowl, and add the butter.
Heat a small amount of water in a saucepan until simmering.
Sit the bowl of chocolate on top. Leave until the chocolate has melted, then stir carefully until smooth.
Carefully spoon the chocolate over the cake and decorate with sugared orange sweets.
Leave to set, then slice and serve