Preheat the oven to 180C/350F/gas mark 4
Use a 20cm/8 inch ring tin.
Grease and line the ring tin. Combine sifted dry ingredients, sugar and pecans. Mash the banana and stir in with the drained pineapple, butter and sour cream. Spoon mixture into tin and bake for 1 hour. Cool for 10 minutes before turning on to a rack.