Pre-heat the oven to 180°C and line a muffin tin with baking paper (or use individual muffin liners).
In a large bowl, sift flour, baking powder, baking soda, cinnamon and salt.
In a separate bowl, combine pineapple, banana, oil, yogurt, sugar, and mix well. Fold wet mixture into the sifted dry ingredients until just combined.
Fill each muffin hole ¾ the way full and bake for about 20 minutes. Allow pan to cool for 10 minutes before turning out muffins to finish cooling on a wire rack.