1 tsp baking powder
225g/8oz light brown muscovado sugar
150²µ/5½´Ç³ú icing sugar, sifted
225g/8oz self-raising flour
75²µ/2½´Ç³ú walnuts
25g/1oz walnut halves
250g/9oz fudge, roughly chopped
225g/8oz butter, softened, plus extra for greasing
150²µ/5½´Ç³ú butter, softened
4 large free-range eggs