Set aside to cool. For the crumble topping, add the flour to a mixing bowl and rub in the butter until the mixture resembles fine breadcrumbs and no large lumps of butter are left. Stir in the ...
Pour blueberry mixture onto ... until blueberries start to burst and topping is slightly browned. Serve over yogurt or with ice cream. To make into crumble bars: Add 2 additional large eggs ...
Rhubarb, apple and blueberry: Reduce the rhubarb to 300g/10½oz and add 125g/4½oz fresh or frozen blueberries to the fruit mixture, just before adding the crumble topping.