Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan.
In a large mixing bowl, combine the mashed bananas, granulated sugar, and brown sugar. Mix well until it's smooth.
Add the melted butter to the banana mixture and mix until fully incorporated.
Stir in the eggs one at a time, followed by the vanilla extract and espresso powder.
In a separate bowl, whisk together the baking soda, salt, and flour. Gradually add the dry ingredients to the wet mixture, stirring just until combined.
Fold in the chocolate chips and chopped walnuts (if using) until evenly distributed.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake for 60-65 minutes, or until a toothpick inserted into the center comes out clean.
Allow the banana bread to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.
Notes
Slice the banana bread and serve it warm with a dusting of powdered sugar on top. You can also accompany it with a dollop of whipped cream or a scoop of vanilla ice cream for an extra touch!