Preheat the oven to 180 C / Gas 4. Grease and flour a 23x33cm cake tin or baking dish.
In a large bowl, stir together 250g sugar, bicarb, salt and 250g flour. Stir in the eggs and soured cream until smooth, then fold in the rhubarb. Pour into the prepared dish and spread evenly.
In a smaller bowl, stir together the remaining sugar and butter until smooth. Rub in remaining flour until the mixture is crumbly. Sprinkle the mixture on top of the cake then dust lightly with cinnamon.
Bake in the preheated oven until a skewer inserted in the centre comes out clean, about 45 minutes.
delicious and so easy to make,made this twice everyone loves it. next time im going to add more fruit and try something else instead of rhubarb. i mixed a couple of teaspoons of cinnamon with the sugar for the topping to suit our taste. - 10 Sep 2011
Found this while I was looking for something to do with a glut of rhubarb in my garden - makes a nice difference to the usual crumbles and pies. A lovely moist cake and crumble topping ads extra texture - a large amount of sugar in the recipe but did not taste too sweet because of the tartness of the rhubarb. Just a couple of points about the recipe - I would normally rub the butter into the mixture of sugar and flour for a crumble and would recommend mixing the cinnamon through the crumble mix rather than sprinkling it on top. - 23 Sep 2013