Preheat the oven to 180?C/160?C fan/gas mark 4. Grease two 23cm round cake tins.
In a medium bowl, stir together the flour, cinnamon and sugar. Add the oil and eggs, mix until blended, then stir in the carrots and nuts. Divide the cake mixture evenly between the two prepared tins.
Bake for 25 to 30 minutes in the preheated oven. A skewer inserted into the cake should come out clean. Cool cakes on wire racks before removing from tins.
To make the icing, cream together the butter and cream cheese. Add the sugar and cream well. Stir in the nuts and vanilla. Use to fill and ice the cooled cake layers, reserving a few tablespoons.
Colour one-quarter of the reserved icing with green food colouring, and colour the rest with a mixture of the red and yellow to make an orange colour. Pipe the icing onto the cake to make mini carrots. Serve with Avonmore Fresh Dessert Cream.