Directions

1. Line the base and sides of a shallow 18.5cm (7in) square tin with cling film.
   Put the chocolate into a saucepan with the butter and syrup. Heat it gently, stirring occasionally, until it is melted.
   Remove the chocolate mixture from the heat. Put the biscuits into a plastic bag and crush them into small pieces with a rolling pin.
   Stir the biscuits, ginger and sultanas into the chocolate mixture until they are evenly coated. Spoon into the tin, level the surface and chill for 2-3 hours.
   To serve now: Lift the cling film out of the tin and peel it away. Cut the mixture into 16 squares. They will keep in an airtight container for a few days.
   To freeze: Carefully place the squares to be frozen in rigid plastic containers in a single layer or between sheets of greaseproof paper. Cover, seal and label. Use within 1 month.
   To serve from the freezer: Thaw as many slices as required at room temperature on a wire rack for about an hour or until thoroughly defrosted.