Cream together the butter or margarine
and sugar until light and fluffy. Gradually beat in the eggs, then
fold in the flour. Puree the raspberries, hen rub through a sieve
(strainer) to remove the pips. Stir the puree into the cake mixture,
just so it marbles through the mixture, and is not mixed in. Spoon
into a greased and lined 20 cm./8 in cake tin (pan) and bake in a
preheated oven at 180°C/350°F/gas mark 4 for 45 minutes until well
risen and springy to the touch. Transfer to a wire rack to cool.
Spread the butter icing over the cake
and roughen the surface with a fork. Melt the chocolate in a
heatproof bowl set over a pan of gently simmering water. Spread over
a baking (cookie) sheet and leave until almost set. Scrape the flat
of a sharp knife across the chocolate to make curls. use to decorate
the top of the cake.