Preheat the oven to 180'C / Fan 160'C / Gas Marl 4 and grease and line a 2lb pound loaf tin. Mix the butter, sugar and lime zest in a large mixing bowl using an electric whisk until pale and fluffy. Add the eggs and milk and mix again until combined.

Add the flour, desiccated coconut and xantham gum to the mixture and fold in using a wooden spoon or spatula. Once combined, pour the mixture into the baking tin and smooth out.

Bake for 45-50 minutes, until a skewer inserted in the middle comes out clean. Remove the cake from the oven and place (still in the tin) on a cooling rack for 10-15 minutes while you make the syrup.

Mix the caster sugar and lime juice for the syrup in a small saucepan. Heat on a low heat, stirring until the caster sugar has dissolved. While the cake is still warm, prick it with a skewer all over and then use a spoon to cover the cake in the warm syrup. Do this spoon-by-spoon to ensure an even coverage and let it all soak in.

Leave the cake to cool completely. Once cool, make the icing by sifting the icing sugar into a bowl and gradually adding the lime juice until you get the desired consistency (I like mine nice and thick!). Pour over using a spoon (tip: start in the middle of the cake to get a lovely drip effect as it runs out and over the edges). Sprinkle with lime zest and some extra desiccated coconut, leave to set and then serve.