Preheat the oven to 200 degrees Celsius.
Rub the flour, 50g sugar, butter and the ground almonds together with the tips of your fingers so that you obtain a fine crumble. Spread this out evenly on a baking tray. Bake the crumble for about 7-11 minutes in the oven until golden brown.
Make a syrup with the water and the 100 g sugar: mix the sugar and water together, bring to the boil and leave for about 2 minutes until you have a clear syrup. Set aside and allow to cool.
Place the frozen raspberries in a food processor and add the cooled sugar syrup. Blend until smooth.
Serve in a glass ramekin and top with the crumble.
«This sorbet can be made slightly in advance but make sure to freeze it in individual portions and not for more than about thirty minutes - any longer and the sorbet will form a solid block.»