- 225 g (8 oz) softened butter
- 225 g (8 oz) light muscovado sugar
- 275 g (10 oz) self-raising flour
- 2 level teaspoons baking powder
- 4 large eggs
- 2 tablespoons milk
- 2 tablespoons coffee essence
- 75 g (3 oz) chopped walnuts
For the icing
- 75 g (3 oz) softened butter
- 225 g (8 oz) sifted icing sugar
- 2 teaspoons milk
- 2 teaspoons coffee essence
- walnut halves
Pre-heat the oven to 180°C/Fan 160°C/Gas 4.
Grease a 30 x 23 cm (12 x 9 in) traybake or roasting tin then line the base with baking parchment.
Measure all the cake ingredients into a large bowl and beat until well blended. Turn the mixture into the prepared tin and level the top. Bake in the pre-heated oven for about 35–40 minutes or until the cake has shrunk from the sides of the tin and springs back when pressed in the centre with your fingertips.
Leave to cool in the tin.
To make the icing, beat together the butter with the icing sugar, milk and coffee essence. Spread evenly over the cold cake using a palette knife, then decorate with the walnut halves and cut 21 pieces.
If you like, you can use instant coffee granules instead of coffee essence. Mix 2 teaspoons with 2 tablespoons of water.
Mary Berry’s Baking Bible published by BBC Books, £20, photography copyright Dan Jones