Just wanted to let you all know that I made these, and modified them with much better results (in both my, and in my tasters' opinions).

The first time I made them I reduced both the sugar to a 1/3 of a cup and the oil to a 1/4 of a cup (making up the rest of the liquid content with milk), but still found them overly sweet and way too oily. The second time I made them I used the following:

* 2 cups self-raising flour
* 1/4 cup caster sugar
* 1 cup natural yoghurt
* 1 egg
* 1 tbsp vegetable oil
* 1/2 cup milk
* 2 large bananas, mashed (1 cup)
* 1 tbsp sweet spices mix (I used Herbies Sweet Fragrant Spice mix, but you could use 1/4 tsp cinnamon and 1/4 tsp nutmeg instead).
* 1 tablespoon (approx, maybe a little more) rosewater

This resulted in a slightly denser but still very moist consistency, and the tang of the yoghurt was not masked by over sweetness and it blended really nicely with the sweet spices and rosewater, giving it a suggestion of middle-eastern flavours.