Dissolve the sugar in the evaporated milk over low heat. Remove the pan from the heat and add the desiccated coconut. (If using fresh coconut, it should be finely grated.) Leave to cool for a few minutes, then divide in two. Press the uncoloured portion into a loaf tin, lined with buttered greaseproof paper. Tint the other portion pink with cochineal, press on top. When quite cold and set, turn out and strip off the paper. Roll in icing sugar, and cut in slices.