Preheat the oven to 350°F. Line a loaf pan with parchment paper and set aside.
In the bowl of a stand mixer, cream together the sugar and butter until light and fluffy. Add in the bananas, vanilla and eggs, and mix until fully combined.
In a seperate bowl, mix together the flour, baking soda, baking powder and cinnamon.
Slowly add the dry ingredients into the wet ingredients, mixing until fully incorporated. Fold in the macadamia nuts.
Pour the batter into the prepared pan and bake in the preheated oven for 55-65 minutes, or until a toothpick inserted comes out clean. Allow to cool completely in the pan before cutting into slices.