4 oz (115 g) Plain chocolate
9 fl.oz (275 ml Milk
7 oz (200 g) Light brown sugar
1 Egg yolk
9 oz (260 g) Plain flour
1/2 tsp Salt
5 oz (140 g) Butter or margarine, at room temperature
9 oz (260 g) Caster sugar
1 tsp vanilla essence
For The Icing:
8 oz (225 g) Plain chocolate
1/4 tsp Salt
6 fl.oz (175 ml) Soured cream
1. Pre heat a 350 F/180 C/Gas 4 Oven. Line a 2x 8-9 inch (20-23 cm) round cake tins with grease proof paper.
2. In a heat proof bowl set over a pan of simmering water, or in a double boiler, combine the chocolate, one-third of the milk, the brown sugar and egg yolk. Cook, stirring, until smooth and thickened. Let it cool.
3.Sift the flour, carbonate of soda and salt into a bowl. Set aside.
4. With an electric mixer, cream the butter or margarine with the castor sugar until light and fluffy. Beat in the whole eggs, one at a time. Mix in the vanilla.
5. On low-speed, beat in the flour mixture into the butter mixture alternatively with the remaining milk, beginning and ending with flour.
6.Pour in the chocolate mixture and mix until just combined.
7. Divide the cake mixture evenly between the two tins. Bake until a skewer inserted into the center comes out clean, 35-40 minutes.
8. Let the cake cool in the tins on wire racks for 10 minutes, then unmould the cakes from the tins onto the wire racks and leave them to cool completely.
9. For the icing, melt the chocolate in a heatproof bowl set over a pan of hot, not boiling water, or in the top of a double boiler. Remove the bowl from the heat and stir in the salt and soured cream. Let it cool slightly.
10. Set 1 cake layer on a serving plate and spread with one-third of the icing. Place the second cake layer on top. Spread the remaining icing all over the top and sides of the cake, swirling it to make a decorative finish.