150ml/¼pt sunflower oil, plus extra for the tin
100g/4oz dark chocolate, broken into chunks
200g/7oz self-raising flour
200g/7oz light muscovado sugar
6 tbsp cocoa powder
100ml/3½fl oz soured cream
2 large eggs
1 tsp vanilla extract
1 tbsp instant coffee, dissolved in 1 tbsp hot water
1 Cadbury Flake, crumbled, to decorate
FOR THE ICING
100g/4oz butter, softened
85g/3oz icing sugar
50g/2oz cocoa powder, sifted
1-2 tbsp milk
Heat oven to 160C/140C fan/gas 3. Oil a 23cm round cake tin, then line the base with baking parchment.
Whizz the chocolate into small pieces in a food processor. Tip the flour, sugar, cocoa, oil, soured cream, eggs, vanilla, dissolved coffee and 100ml hot water into a large mixing bowl. Whisk everything together with electric beaters until smooth, then quickly stir in the whizzedup chocolate bits. Pour the batter into the tin and bake for 50 mins-1 hr until risen and springy to the touch. Transfer to a wire rack and leave to cool.
To make the icing, beat the butter in a large bowl until light and fluffy. Add the icing sugar, cocoa and a drop of milk, and beat until creamy. Beat in more milk, if necessary, to loosen the icing to a spreadable consistency. Spread the icing over the top of the cake and sprinkle with crumbled Flake. The cake can be kept in an airtight container for 1-2 days.