Preheat oven to 180°C/fan 160°C/gas mark 4. Grease a 28 x 18cm (11 x 7in) cake tin and line with non-stick baking paper; set aside.
Put brown sugar, rapeseed oil and eggs in a bowl; whisk together using a balloon whisk. Fold in flour, baking powder and cinnamon; fold in grated carrots, sultanas and orange zest.
Transfer mixture to prepared tin; level surface. Bake in oven for about 40 minutes or until a fine skewer inserted into centre comes out clean. Cool in tin for 5 minutes; turn out onto a wire rack, peel off lining paper, then turn cake back over onto another wire rack and leave to cool completely.
In a small bowl, mix icing sugar and orange juice together until smooth. Thinly spread or decoratively drizzle icing over top of cake; leave to set for 10 minutes.
Cut cake into portions and serve.
For a tempting dessert, cut the cold, iced tray bake into 8 portions and serve each portion with a dollop of fat-free, natural Greek-style yoghurt or fromage frais and some fresh raspberries or sliced strawberries.
Leave out the icing and serve warm, sprinkled with a dusting of icing sugar.
The views expressed on this site are not those of the Publisher. Always consult your GP or a health professional before beginning any diet or trying any of the products or advice mentioned in Healthy Diet, particularly if you have a medical condition for which it may not be advisable.