Spread sorted raspberries through a sieve, mix with jelling sugar and yogurt. Beat egg yolks heartily in a water bath until creamy. Make powdered sugar into syrup with water. Stir hot syrup into egg yolk mixture with mixer, remove from water bath, continue beating heartily until mixture cools and sets. Combine raspberry yogurt mixture and egg yolk cream in a baking dish, freeze in the freezer for at least 3 hours.
Stir several times.
Prepare with strawberries or possibly currants.
Tip: The higher the fat content in the yogurt, the more aromatic and creamy the result!