Mix greek yoghurt (0.6-0.83 cals per gram depending on fat) with half the amount of cocoa powder (1.5 cals per gram) and 1/5th the amount of sugar worth of sweetener.
Freeze or refridgerate until you can scoop into balls, then freeze or refrigerate those balls. I like freeze. Alternatively, wrap the mixture in cling wrap and smash it into pieces.
by 6ync