In a bowl, cream together butter and sugar until light and fluffy. Add egg and orange rind and then the flour to form a firm dough.
Take 60g pieces and roll out each to 35.5cm (14in) long, then twist together. Cut twisted length into 4 pieces and place on a baking sheet. Repeat until all of the dough has been used. Chill for 30 mins.
Cook the twists for 15-20 mins, until the edges are just starting to brown.
To make the glaze: Sift the icing sugar into a bowl and mix in the orange juice. Remove the twists from the oven and immediately brush the glaze over each one. Leave to cool before eating - yummy!