In a blender add to it 50g of the raspberries along with the stevia and blend until smooth and put to one side.
In a mixing bowl add the soft cheese, caster sugar, Greek yoghurt and the vanilla essence and using a hand mixer, mix until light and creamy.
In plastic (or glass) sundae containers, spoon in the yoghurt mixture and the raspberry mixture, taking it in turns and making it look pretty.
Freeze it for 4 hours and then serve with fresh raspberries on top.