Preheat the oven to 160 °C.
Grease a 25 cm cake tin.
Cream the margarine and castor sugar but for no longer than three minutes.
Sift together the dry ingredients (except the oat bran) along with the spices.
Add the oat bran and lift the mixture with a spoon to incorporate air.
Add the eggs and egg white one at a time to the margarine mixture, adding 15 ml of the cake flour mixture with each addition.
Beat after each addition for about one minute.
Stir in the remaining dry ingredients.
Finally add the raw carrot, apple and sultanas.
Turn the mixture into the prepared tin and bake for 30 to 45 minutes or until done (a testing skewer inserted into the centre of the cake should come out clean).
Turn out and leave to cool completely.Icing
Mix the ingredients, taking care not to overmix, and spread over the cooled cake.
Nutritional value per slice:
Fat 10 g; Energy 1 102 kJ.