Cream butter, rind and sugar until light and fluffy. Beat in eggs one at a time util well combined.
Stir in apricots and orange juice then sifted flour.
Spread mixture into tin and bake for 20 minutes, 170C, 325F gas 3 until brown and then stand for 10 minutes.
Make the topping, sift icing sugar into small heat proof bowl, add butter, rind and orange juice and stir over hot water until icing is smooth and spreadable. Spread over cake and sprinkle with nuts and leave to cool. Cut into squares and remove from tin.