In a bowl whisk together yoghurt, cocoa powder, milk, syrup, and chia seeds until well combined.
Pour the mixture into a glass container.
Cover and refrigerate for at least 4 hours, until thickened.
Before serving, make the topping by whisking together the ingredients (depending on the protein powder you use you may need more or less yoghurt).
Spread on top and serve with a dusting of cocoa powder.