1) Sieve the raspberries make a puree. Measure just enough water required to make the puree up to 1 pint. Ensure that the water and puree are not mixed together.
2) In the water, dissolve the sugar and bring the mixture to boil. Boil for about 10 minutes, uncovered. Stir the syrup into the raspberry puree and allow to cool.
3) Pour the mixture into a 1 pint ice-cube tray and freeze till the mixture has achieved a mushy consistency.
4) Till they are thick and foamy, whisk the egg whites. Ensure that they are not dry. Fold the whites into the puree and put back in the freezer till firm.
5) Freeze the preparation by covering, labelling and storing in the freezer.
6) Soften slightly for about 5 minutes in the fridge. Serve after spooning into glasses.