First make the nutty crumble topping. Sift 4 oz flour into a bowl, and add 3 oz butter. Do not rub in the fat but cut it in with a pastry blender or a pair of knives used like scissors. Stir in the muscovado sugar and nuts and set aside.
Sift the remaining 6 oz flour and the cinnamon into a separate bowl and reserve. Slice the rhubarb into 1-inch chunks and finely grate the zest of the orange over it. Cream the remaining 1/4 lb butter with the caster sugar until pale, creamy and light. Break up the eggs with a fork and add them to the butter mixture a little at a time, alternating with spoonfuls of the flour and cinnamon and add 2 tablespoons of orange juice.
Spoon the cake mixture evenly over the base of a 9-inch spring-clip tin that has been greased, lined and greased again. Scatter the rhubarb and orange mixture evenly over the top then cover the fruit with the nutty crumble mixture. Bake at 350 F (180 C) gas mark 4 for about 1 1/4 hours.
Leave in a warm draught-free place to cool down slowly after baking and wait until the crumble-cake is completely cold before taking it out of the tin. Wait until the next day before eating.
Source: Philippa Davenport in "Country Living" (British), June 1988. Typed for you by Karen Mintzias