Preheat the oven to 375 F
Roughly chop half the pecans into small pieces and the other half into larger chunks.
Mash the bananas to a mush with a fork and then mix in the yoghurt.
In a bowl, whisk the sugar and butter together until it is smooth and fluffy.
Slowly add the eggs, and then the banana/yoghurt mixture.
Combine the flour, cinnamon and baking soda together in a separate bowl, and then fold into the bowl of wet mixture.
Stir through the small chunks of pecans, and then pour the batter into a greased cake tin.
Bake in the oven for around an hour, it needs quite a long time to cook as it's such a wet batter. To test if it's done, poke a skewer into the batter and check it comes out clean. Remove to a cooling rack.