Preheat the oven to gas mark 5/190°C (170°C in a fan oven.)
In a large bowl, cream together the butter, caster sugar and brown sugar until smooth. Beat in the egg until well blended. Mix in the zest and half of the juice from the Jaffa Oranges.
Combine the flour, bicarb, and salt. Mix in cranberries until evenly distributed.
Drop dough by rounded tablespoonfuls onto ungreased baking trays. Cookies should be spaced at least 5cm apart.
Bake for 12 to 14 minutes in the preheated oven, until the edges are golden. Remove from cookie sheets to cool on wire racks.
For the icing: In a small bowl, mix ½ teaspoon orange zest, the remaining Jaffa Orange juice and icing sugar until smooth. Spread over the tops of cooled cookies. Let stand until set.
