1. Preheat the oven to 180ºC {fan forced} and line the base of two round cake {20cm} tins with baking paper.
2. Place walnuts onto a tray and toast in the oven for 5-10 minutes. Watch them because they go from toasted to burnt quickly. Once toasted, remove from oven and allow to cool, and then roughly chop.
3. In a large bowl, place the flour, bicarb soda, cinnamon, and nutmeg. Stir to combine.
4. In a jug or bowl, place the eggs, sugar, oil, vanilla and buttermilk and whisk until combined. I found it easier to just do this in the jug of my Thermomix, but mixing by hand also works.
5. Combine the wet and dry mixes, and stir to combine. Don’t over mix. Add in the carrot, drained pineapple, coconut, and chopped walnuts. Stir to gently combine.
6. Divide the mix evenly into the two cake tins. Place into the oven and bake for 40-50 minutes, or until a skewer comes out clean when inserted into the centre of the cakes. Allow the cakes to cool slightly, before turning onto a wire rack to cool completely.
7. To make the icing, combine all of the ingredients into a bowl and using electric beaters, mix until smooth. Ice the cooled cakes and decorate.