Preheat oven to 175C.
In a mixing bowl, mash bananas.
Mix in yogurt, eggs, vanilli extract, and melted butter.
Stir in salt & sugar.
Then sift in flour, baking soda, baking powder, cinnamon, and nutmeg.
Mix until just combined.
Fold in chopped walnuts.
Bake 50-60 minutes or until skewer inserted comes out clean.
Allow to cool in pan for 10 minutes before unmoulding to cool completely on a cooling rack.