Soften gelatine in cold water.
Heat over hot water until dissolved.
Whip cream until thick then beat in icing sugar.
Blend in sherry and beat in dissolved gelatine.
Chill until thick enough to spread, folding occasionally.
Use as a filling for three sponge- or chiffon-cake layers, or as a swirled topping on a 9 X 13-inch cake.
Chill before serving.
If used as a topping, drizzle with chocolate or orange glaze.