Preheat the oven to 160C/325F/gas mark 3
Use a 900g/2 lb loaf tin.
Grease the loaf tin, line with greaseproof paper and grease the paper. Cream butter and sugar in a small bowl until light and fluffy. Stir in mixed peel, flour and sour cream and mix well. Spread mixture into prepared tin. Bake the oven for 11/4 hours. Stand for 5 minutes before turning onto wire rack to cool. Dust with icing sugar before serving.
