Preheat the oven to 170C/325F/Gas Mark 3. Grease and line 3 x 20cm cake tins.
Blend the sugar, eggs and oil in a bowl - I use my trusty Kenwood Chef with the beater attachment - and don't worry, it will look slightly split at this stage!
Carefully add all the dry ingredients and mix well for a few more minutes.
Stir in the grated carrot and mix well and divide the mixture into the three tins.
Bake for 20-25 minutes, until the cake begins to come away from the side of the tin.
Leave the cakes to cool slightly in the tins, then turn them out and leave them to cool completely.
Blend all of the ingredients together for at least 5 minutes, but take care not to over beat or the mixture will go runny!
When the cakes have cooled, sandwich them together with the frosting and carefully dust over some ground cinnamon. Delicious!