Preheat oven to 180C/350F and grease a loaf tin. I usually just spray a couple of times with low cal cooking spray and spread that around with a piece of kitchen towel.
Sift all of the dry ingredients, the 2 types of flours, bicarbonate of soda, salt, baking powder, cinnamon and sugar into a large mixing bowl, or stand mixer bowl.
In a separate pyrex bowl, add the wet ingredients by mashing the bananas first with a potato masher or fork, then add the yogurt, eggs, oil and vanilla extract. Mix together.
Pour the wet ingredients into the larger bowl with the dry ingredients. Fold all of the ingredients together either using the stand mixer paddle attachment or a spatula.
Pour cake mixture into loaf tin and bake for 45 minutes until well risen and golden brown.
Check the loaf has cooked by inserting a wooden skewer / cocktail stick into the centre which should come out clean if cooked then remove from the oven.
Allow to cool slightly in the tin before removing and transferring to a wire baking rack.
Once completely cooled either store in the fridge or slice into 15 slices and freeze.