1. Place the raspberries in a medium saucepan and add the raspberry preserve. Warm over a low heat for about 5 minutes or until the raspberries are pulpy, stirring occasionally.
2. Press the raspberries and juice through a nylon sieve into a bowl; discard the seeds in the sieve. Stir in the rosewater and crème de cassis, if using. Whisk in the yogurt until smoothly blended. Taste the mixture and sweeten with the icing sugar.
3. Pour into an ice cream machine and freeze according to the manufacturer’s instructions. When you have a smooth and creamy frozen mixture, spoon it into a large freezerproof container. Freeze for at least 1 hour. If you do not have an ice cream machine, pour the mixture straight into a large freezerproof container and freeze for 1 hour or until set round the edges. Beat until the mixture is smooth, then return to the freezer. Freeze for 30 minutes, then beat again. Repeat the freezing and beating several times more until the raspberry frozen yogurt has a smooth consistency, then leave it to freeze for at least 1 hour.
4. If storing in the freezer for longer than 1 hour, transfer the raspberry frozen yogurt to the refrigerator 20 minutes before serving to soften slightly. Decorate with raspberries and mint, if desired.

PER SERVING

152 calories
4 g protein
5 g total fat
3 g saturated fat
18 mg cholesterol
23 g total carbohydrate
22 g sugars
4 g fibre
44 mg sodium

Although Greek-style yogurt is regarded as very rich and creamy-tasting, it has relatively few calories compared to 35% whipping cream.