I saw a recipe online for something similar so decided to change a few bits and make my own version.
You will need:
2 sachet of gelatine
1 tbsp Cocoa powder (1.5 syns)
3 tbsp sweetener
1/4 pint of boiling water
2 tbsp of vanilla Muller light yoghurt
Mix everything together in a bowl. Pour into moulds (I used a ice cube tray) pop into fridge for about 30 mins or set. I made about 20 sweets and 1.5syns for the whole lot.