Beat butter and fair trade sugar in a bowl with an electric mixer until light and creamy. Fold in combined sifted cornflour, plain flour and fair trade cocoa. Mix in coffee (either instant which has been disolved or take 2 teaspoons of your plunger/espresso coffee).

Roll 2 teaspoons of mixture into balls. Place about 2cm apart on oven trays lined with baking paper. Flatten slightly with the back of a spoon.

Cook biscuits in a moderate oven (180°C) for about 8 minutes, or until lightly browned. Stand biscuits on trays for 5 minutes, before transferring to a wire rack to allow to cool.

Place fair trade chocolate in a medium heatproof bowl over a small pan of simmering water. Stir over heat until chocolate is smooth. Place a biscuit on a fork and dip into chocolate mixture to coat all over. Shake off any excess chocolate. Place on a tray lined with baking paper. Repeat with remaining biscuits and chocolate. Refrigerate the biscuits until set.