1. Preheat the oven to 160°C / 325°F / gas 3. Using a little oil, lightly grease the base and sides of a deep roasting tin (around 20cm x 30cm) and line the base with parchment paper.
2. Put the raisins and stem ginger (if using) in a bowl and add the zest of the orange. Squeeze in the juice. Mix and leave to soak while you make the cake batter.
3. In a bowl mix together the wholemeal flour, self raising flour, baking powder, bicarbonate of soda and cinnamon powder.
4. Separate 2 eggs. Place the whites in a large bowl and whisk together with a pinch of baking powder until they form soft peaks.
5. Add the yolks to another large bowl, adding the remaining egg and pour in the sugar. Mix together until the are foamy before you start pouring in the oil a little at a time until well mixed.
6. Add in half the flour mixture and mix well before adding in the rest.
7. Fold in the carrots and raisins, including all the juice, followed by the firm egg whites.
8. Pour into the lined tin and shake the tin to level it out.
9. Bake in the centre of the oven for 40 - 45 minutes. Test it by inserting a skewer into the centre, it should come out clean.
10. Leave to cool in the tin for around 10 minutes. In the meantime make the cream cheese frosting by whisking all the ingredients together. Taste and add more icing sugar if you like. Pop in the fridge until you need it.
11. Turn out the cake onto a wire rack and leave to cool completely.
12. Cut the cake horizontally through the middle so you have two layers. Spread half the cream cheese frosting on top of one layer, and then put the other cake layer on top. Spread the remaining cream cheese frosting on top. Cut into large squares.
Anjali's Tip Sometimes I like to sprinkle over some freshly grated chocolate as a little extra treat. Kinda means it isn't that low fat but a little chocolate never hurt me! Keep the cake in an airtight container in the fridge for up to a week, making sure you let it get to room temperature whenever you need it.