Preheat oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line with parchment paper.
In a bowl, whisk together flour, baking soda, salt, and cinnamon. Set aside.
In another bowl, mix melted butter and brown sugar until smooth.
Add eggs, vanilla, mashed bananas, and crushed pineapple. Stir well.
Gradually fold dry ingredients into the wet mixture. Do not overmix.
Gently stir in shredded coconut and nuts (if using).
Pour batter into the prepared loaf pan.
Bake for 55-60 minutes, or until a toothpick inserted comes out clean.
Let cool in the pan for 10 minutes, then transfer to a wire rack.
Slice once fully cooled. Enjoy warm or toasted with butter!
