Afghans are a rich chocolate cookie from New Zealand, they are spiked with crunchy cornflakes and topped with generous dollops of silky chocolate icing. Traditionally they are garnished with a walnut half, but feel free to ad-lib; pecans, sliced almonds or even slices of fresh strawberry make for a nice change. —Emma Galloway | My Darling Lemon Thyme
Preheat oven to 180 C/350 F. Grease 2 oven trays and line with baking paper.
Cream margarine and sugar together in a large bowl until light and fluffy, using either a wooden spoon or electric mixer. Sift over brown rice flour, tapioca flour, sweet rice flour, guar gum and cocoa powder. Mix using a wooden spoon until fully combined. Add cornflakes and continue to mix to incorporate (I usually use my hands at this stage, so much easier!). The mixture will be really wet and sticky, that's perfect.
Using your hands, gently roll tablespoons of mixture into small balls. This will be really sticky work, so just do your best. Place onto oven trays about 2cm apart. Slightly flatten each using a fork or your fingers. Bake for 10-12 minutes until set. They will firm more on cooling. Remove from the oven and cool on the tray. Ice once completely cold, by dolloping a generous spoonful of chocolate icing on each cookie, and top with walnuts or pecans.
To make the icing, sift icing sugar and cocoa into a bowl. Add the melted margarine, vanilla and just enough boiling water to form a thick icing.