Step 1

Preheat the oven to 350°F (175°C). Grease a loaf pan (9x5 inch loaf pan).

Step 2

Add the walnuts on a rimmed baking sheet, slide in the oven and toast until fragrant, 5 to 10 minutes. Let cool.

Step 3

In a large bowl, combine the flour, walnuts, brown sugar, baking soda and salt. In a medium bowl, stir the mashed bananas, yogurt, eggs, butter and vanilla with a spoon. Add rum, if using. Lightly fold the banana mixture into the dry ingredients with a rubber spatula, mixing just until combined. The batter should be thick and chunky. Scrape the batter into the loaf pan.

Step 4

Bake the banana bread until the surface appears golden brown and a cake tester inserted in the center comes out clean, about 55 minutes. Let cool the banana bread in the pan for 5 minutes. Remove from the loaf pan, slice and serve warm.