Preheat oven to 180 C / Gas 4. Grease and flour a 25cm tube cake tin.
Into a large bowl, sieve together the flour, sugar, bicarbonate of soda, cinnamon and salt. Make a well in the flour mixture. Add the mashed bananas, oil, vanilla, eggs and pineapple. Fold in nuts. Pour cake mixture into prepared tin.
Bake in the preheated oven for 90 minutes or until a skewer inserted into the centre of the cake comes out clean. Allow to cool completely on wire rack.