Crush wine biscuits by putting them inside a plastic kitchen bag and rolling them with a rolling pin until resembling large breadcrumbs.
Pour butter mixture over biscuits, and mix in cocoa, sultanas and coconut.
Press into a slice tin then ice.
To make chocolate icing, mix icing sugar, second measure of cocoa powder, second measure of butter and water together - butter and water amounts vary according to personal taste. Too much water and the icing won't set well.
Slice when cool, and store in fridge. Also freezes well.