makes enough for a 22 - 24 cm (8 1/2 - 9 1/2 in) cake
100 g (4 oz) plain chocolate
7.5 g (1/2 tbsp) unsalted butter
165 ml (5 1/2 fl oz) water
90 g (3 1/2 oz) granulated sugar
1. Melt the chocolate and butter together with 1 tbsp of boiling water in a heat-proof bowl set over simmering water.
2. Draw off the heat and stir to blend.
3. Put the water in an unlined copper sugar boiler or heavy-based pan, add the sugar and boil to the 'thread stage'; dip a pair of scissors into the mixture and when the blades are opened, the syrup will form a thin thread between the points.
4. Stir the chocolate liquid straight into the syrup and replace the pan on the heat.
5. Boil gently for 5 minutes when the icing will have thickened.
6. Test a few drops on a plate — it should feel sticky.
7. Pour the icing straight over the apricot-glazed cake, tipping the wire rack back and forth so that the icing runs all over the top.
8. Do not use a spatula on the surface, but smooth more on the sides.
9. Decorate with fruits and nuts immediately, although piped decorations should be applied when the chocolate icing has cooled completely.
10. The icing will set with a high gloss but will dull a little after 24 hours.
11. The cake may then be stored in the refrigerator without spoiling.