Preheat oven to 170°C (150°C fan) mark 3. Grease and line the base and sides of a round 20.5cm (8in) cake tin with parchment paper. Put the oil, sugar and eggs into a large bowl and whisk together until smooth. (I used a food processor with the Cake / Bread attachment and pulsed)

Add the flour, soda and spices to the bowl and mix to combine. Stir in the sultanas, carrots and nuts. Scrape mixture into the prepared tin, level and bake for 1hr 5min-1hr 15min or until a skewer inserted into the centre comes out clean. Leave to cool for 5min in tin, then remove from tin and leave to cool completely on a wire rack

To make the icing, in a large bowl beat the butter and vanilla until completely smooth, then add the room-temperature cream cheese and mix to combine. Sift over the icing sugar and mix (carefully at first, as otherwise there will be clouds of icing sugar) until smooth and fluffy

Cut the cooled cake in half horizontally through the middle. Use half the icing to sandwich the halves back together and place cake on a cake stand/plate. Spread remaining icing over top of the cake and lay on the carrot decorations, if using. Serve in slices.