1. Grease and line the tins. Pre-heat oven to 180ºC/160ºC fan/Gas 4.
2. Place into a large bowl, the oil, eggs, sugar, carrots and orange rind. Mix together well with a wooden spoon or in a mixer.
3. Mix flour, salt, bicarbonate of soda and mixed spice, and sieve into the wet ingredients. Lightly mix all ingredients together until well combined.
4. Pour into prepared tins, and bake for 40-45 mins until soft and springy to touch. Remove from oven and leave in tins for 5 mins to cool slightly, before turning out onto cooling rack. Peel off the paper. Cool completely.
5. For the frosting - place butter, icing sugar and lemon rind into a bowl, and beat well to combine. Stir in cream cheese. Place in fridge for 15 mins to firm up.
Fill and top the cake with the frosting.
6. Decorate with carrot sugar decorations (06381) or make your own from sugar modelling paste.