Place the caster sugar, glucose, butter and water in a small heavy-based saucepan, then cook over medium heat for 10–12 minutes or until the mixture reaches a medium caramel colour. Add the bicarbonate of soda, salt and shredded coconut and cook for 1 minute, stirring, until the mixture is a darker caramel colour. Immediately pour onto a silicone mat on a baking tray and le