Line a 2lb loaf tin (standard size) with greaseproof/parchment paper.
Preheat the oven to about 180C/160C Fan.
Whisk together your oil and eggs.
Mix together your sugar, gluten free flour, cinnamon, all spice and bicarbonate of soda in a large bowl.
Add to your bowl the grated carrot, a few tbsp of the juice from your orange (optional) and the orange zest, chopped pecans and walnuts and the egg/oil mixture. Then mix thoroughly with a wooden spoon.
Pour/spoon into your loaf tin and bake in the middle of your preheated oven for around 50 - 55 minutes, or until a skewer comes out clean. Leave the cake to cool in the tin.
Whilst your gluten free carrot cake cools, make the icing. Beat together all your icing ingredients in a bowl, ensure your icing sugar is sifted and you might also choose to add some more icing sugar if you want a thicker consistency (I usually make my icing by hand but you can use an electric whisk if you prefer).
Spread over the top of your completely cooled gluten free carrot cake and then liberally sprinkle with crushed pecans and walnuts.
* You can ice your carrot cake loaf however you like, I always think some sort of cream cheese icing is the way forward though!