Mash the raspberries with a fork until smooth, then add the sugar and orange juice and stir.
Divide half the mixture between 4 ice lolly moulds. Wipe the sides of the moulds clean then add a generous tablespoon of yogurt on top of each layer of raspberries. Top with a further layer of raspberries.
Add lolly sticks and freeze for 4-5 hours or overnight until firm.
Run lolly moulds under a hot tap and the lollies will slip out easily.