Preheat the oven to 350 F degrees
In a mixing bowl, combine all dry ingredients : flour, baking soda, baking powder, salt. Mix well
In another mixing bowl, mix the butter and sugar with stand mixer or hand held mixer. until the texture is light and fluffy.
Add banana, eggs, 1/2 of the dry mixture and 1/2 of the nuts. mix well
Pour the rest of the flour and mix together. Do not over mix it.
Grease the loaf pan, pour the batter mixture , and sprinkle the rest of nuts on top
Bake for 55 Minutes at 350 f degree oven, until it turns slightly brown on the edge. (or until a toothpick inserted near the center comes out clean.
Let it cool for 10 - 30 minutes, and slice it into your desired size.