Walnut banana cake

Sift the flour and mix with soda and salt. Beat the oil with sugar until air cream. Mash the bananas with sour cream and mix with the oil mass. Add a third of the flour mixture, stir and add a third of the yogurt. Mix everything well and add a third of the flour and yogurt again in turn. So introduce all products, thoroughly kneading each time. Mix the dough with the chopped nuts. Grease two 23cm moulds with butter and sprinkle with flour. Spoon the dough into the moulds and bake in the oven for about 30 minutes.