Preheat oven to 180°C, 160°C fan oven, Gas mark 4. Place the flour in a bowl. Add the Stork cut into small pieces. Rub in until the mixture resembles breadcrumbs. Sprinkle in the brown sugar.
Wash the rhubarb and cut into 1-2 cm pieces. Add the sugar, grated ginger and lemon zest and mix well. Stir in the raspberries. Place the fruit into heat-proof ramekins and cover generously with the crumble.
Place the ramekins in the oven and bake about 30 minutes until the crumble takes on a golden brown colour. Take ramekins from the oven and allow to cool.