Preheat the oven to 350. Grease two loaf pans.
In a small bowl, mash bananas, brown sugar, vanilla extract, and ground cinnamon.
In a large bowl, cream butter and sugar together until light and fluffy.
Add in eggs and beat until mixed.
To the wet ingredients, sift in flour, baking soda, and salt.
Stir until just combined. Add in yogurt and stir.
Pour in mashed bananas, and mix until combined.