Preheat your oven to 350°F (175°C) and prepare a 9×5-inch loaf pan by greasing it with butter and dusting it with flour or lining it with parchment paper.

In a medium bowl, mash the 3 ripe bananas until smooth. Add in the 2 large eggs and 1 teaspoon of vanilla extract, mixing well.

In a separate large bowl, whisk together the 1.5 cups of all-purpose flour, 1 teaspoon of baking soda, 0.5 teaspoon of ground cinnamon, 0.25 teaspoon of ground nutmeg, and 0.5 teaspoon of salt.

Pour the banana mixture into the bowl with the dry ingredients, add the 0.5 cups of softened butter, and stir gently until just combined.

Pour the banana bread batter into your prepared loaf pan, smoothing the top with a spatula.

Place the loaf pan in the preheated oven and bake for 50-60 minutes. Check for doneness with a toothpick.

Remove the banana bread from the oven and let it cool in the pan for about 10 minutes before transferring it to a wire rack.