Since this is an Old-Fashioned Rhubarb Crumble, I have NOT used oats. Feel free to add them, if you want (just swap out half the flour in the topping for oats and call it whatever you want).
I love the generous crunchy topping on the fruit crumble, which is bursting with wintery flavours. I have used rhubarb and apple, plus you can add a few frozen raspberries or some of those home ...
Fill an ovenproof dish about 4cm/1½in deep with the rhubarb. Rub the butter into the flour then mix in the demerara sugar to make the crumble topping. Sprinkle over the rhubarb and bake for 35 ...