Mix one third of the yoghurt with the chocolate powder. Mix the remainder of the yoghurt with the agave syrup and vanilla sugar. First pour the chocolate yoghurt into the moulds, then fill with the remainder of the yoghurt. Finally, mix the two gently with a wooden skewer, pulling the skewer back and forth several times.
Place the moulds in the freezer for 4-5 mins.
Place the icing bag in hot water for approx. 10 mins. to melt the icing. Briefly dip the ice lolly moulds in hot water, remove the lollies from the moulds and dip the tips in the chocolate icing one by one.