Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan or line it with parchment paper.

In a large mixing bowl, mash the bananas until smooth. Stir in the melted butter, sugars, eggs, sour cream, and vanilla extract until well combined.

In a separate bowl, whisk together the flour, baking soda, salt, cinnamon, and nutmeg. Add this to the wet ingredients and gently fold everything together until no streaks of flour remain. If you’re adding nuts or chocolate chips, fold them in now.

Pour the batter into your prepared loaf pan and smooth the top. Bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean. Check at the 50-minute mark to ensure it doesn’t overbake.

Let the banana bread cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely