Step by step
Blitz together the cold butter, flour and sugar in a food processor until you get a coarse crumbly mixture
Tips
If you want to make your berry fruit crumble even sweeter and more delicate, you could enrich it with some lovely juicy raspberries, blackberries or blueberries. Another excellent option is the apple crumble, widespread and well-loved in the Anglo-Saxon world.
Trivia
The name of this dessert derives from its characteristic "crumbly" topping.