Preheat the oven to 350 degrees.
Sift together the flours, baking powder, and salt. Set aside.
In a mixing bowl, cream the butter and sugar together. Add the eggs and banana and stir to incorporate
Add the flour mixture to the batter, in two or three parts. Mix until well combined. Fold in the nuts.
Pour batter into a well-buttered loaf or cake pan. Bake one hour. Let cool. Enjoy!