Banana Bread

Ingredients

3 medium to large ripe bananas
110 g  (4 oz) margarine or butter
225 g  (8 oz) caster sugar
2 eggs
285 g (10 oz) plain flour
5 ml (1 tsp) salt
5 ml (1 tsp) vanilla essence
60 ml ( 2 1/2 fl oz) soured cream
50 g - 100g  (2-4 oz) walnuts , chopped