Preheat the oven to 160C/325F/gas mark 3
Use a 20cm/8 inch ring tin.
Grease the ring tin. Line the base with greaseproof paper. Grease the paper. Sift together the flour, cinnamon and nutmeg in bowl. Stir in the sugar and grated carrot. Combine the oil and sour cream. Stir into the flour mixture. Pour the mixture into the prepared tin. Bake in for about 50 minutes. Turn on to wire rack to cool. When cold, spread with icing. Decorate with walnut halves.
Icing: Beat the cream cheese, butter and lemon rind in small bowl until light and fluffy. Gradually beat in the sifted icing sugar. Beat until combined.
