Place sugar, butter, and yogurt into heavy-based saucepan.
Stir over low heat until sugar is dissolved. Bring to the boil.
Boil without stirring until 115oC or soft ball stage is reached.
Remove from heat. Leave for 4-5 minutes.
Add flavouring and coconut and beat until mixture is thick and creamy.
While still warm but firm, cut into squares. Leave until completely set before removing from tin.
Syrup forms a soft ball when dropped into cold water.
It loses form when removed from the water.
Do not over cook or it will caramelize.