Preheat oven to 375F.

In a bowl, sift together flour, baking powder, and salt.

In a separate bowl, whisk mashed bananas, eggs, melted butter, sugar, cinnamon, and vanilla extract.

Add mixed dry and wet ingredients together. Fold in walnuts.

Pour into oiled or llined baking pan.

Bake at 375F for approximately 60 mins.