Line 7� cake tin with greaseproof paper. Cream 6oz butter & 6oz caster sugar. Beat in 3 eggs one at a time.
Fold in 6oz sifted flour & add 2 tbs cold milk with last tbls.of flour. Add grated rind of one orange then bake at 350deg f for 1 hour or until well risen and golden brown.
When nearly cool make slits across top of cake with sharp knife (or puncture with kniting needle) then drizzle the orange syrup or liquer across top so that it soaks into the cake. Cover the cake in melted cake melting chocolate and leave to cool and set.
Mandarin segments as decoration on top are lovely if the cake will be eaten quick, just make sure the icing has pretty much set and the segments aren�t too wet and juicy so it doesn�t go soggy. Try taking some out of a can and popping them on a plate in the fridge for a while with some kitchen towel underneath to soak up excess juice. Glazing them could also help.
For a more chocolatety cake you could always add some cocoa powder to the cake mix or some coffee for an extra kick.
Melted dark chocolate covering would also go nicely with the tart orange.