Give the yogurt a good stir, then place it in a bowl. Drizzle in the maple syrup to sweeten (optional). Add the desiccated coconut and stir well to mix in.

Find a baking tray that fits into your freezer. Line the baking tray with baking paper or tinfoil. Pour the yogurt onto the lined tray and spread out into an even layer. Top with the cranberries and pistachios, pressing gently into the yogurt.

Pop into the freezer and freeze for two hours or overnight, until solid and frozen through. Break into pieces to serve. For the best texture, leave for a minute or two to soften slightly before serving.

Store any pieces of leftover bark in an airtight tub or bag in the freezer until needed.