Preheat oven to 350°F. Whisk flour, baking soda, baking powder, salt, and cinnamon in a medium bowl.

In a large bowl, mash bananas. Stir in melted butter, brown sugar, eggs, vanilla, pineapple, and sour cream until combined.

Add dry ingredients in two additions, folding just until no streaks remain. Fold in coconut and macadamia nuts.

Scrape batter into a greased, parchment-lined 9x5-inch loaf pan. Bake 55 to 65 minutes, until a toothpick comes out with moist crumbs. Tent with foil if browning too fast after 45 minutes. Cool in the pan 10 minutes, then lift out.

Let the loaf cool completely on a wire rack, about 1 hour, before slicing with a serrated knife.