Rinse the raspberries under cold water and gently pat them dry.
In a small saucepan, combine the sugar and water over medium heat. Stir until the sugar dissolves completely. Remove from heat and add lemon juice; let cool slightly.
Blend the raspberries with the cooled syrup until smooth.
Pour the mixture into a shallow dish and freeze for 4-6 hours, stirring every hour to achieve a light texture.
