Place the chopped cacao in a small heatproof bowl. Pour the hot water or coconut milk over the cacao. Stir gently until fully melted and smooth. Let it cool slightly. It's best to use as little as possible so the mousse remains thick.
In a small bowl, whisk together the yoghurt, honey, vanilla extract, and sea salt. Slowly pour in the melted cacao, stirring continuously until fully combined.
Spoon into serving cups and refrigerate for at least 30-60 minutes to thicken. Before serving, sprinkle with extra sea salt and dark chocolate shavings for a little crunch.
