Preheat oven to 350°. Grease a loaf pan; set aside.
In a small bowl, whisk together flour, baking powder, salt, and cinnamon; set aside.
In a large mixing bowl, beat together sugar and butter until fluffy. Add in eggs, bananas, maple syrup, and vanilla, beating until smooth.
Add dry ingredients to wet ingredients in 3 parts, mixing until smooth after each addition. Fold in walnuts.
Pour batter into prepared loaf pan and bake for about 1 hour until a toothpick inserted in the centre comes out clean. Let cool for 15 minutes in pan, then transfer to a wire rack to cool completely.
Recipe by Port and Fin at https://portandfin.com/maple-walnut-banana-bread/