Preheat oven to 350°F. Butter and flour a 9×5 inch loaf pan.
In a bowl, combine the flour, baking powder, and salt. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and sugar on medium high speed until light and fluffy. Add the eggs one at a time, mixing after each. Scrape down the sides of the bowl and add the mashed banana, lemon juice, and bourbon and mix until just combined.
Add the dry ingredients and mix until just combined. Stir in the walnuts and chocolate chips. Pour batter into the prepared loaf pan and spread to distribute it evenly. Bake for 50-60 minutes or until a toothpick inserted into the center comes out clean. Let cool in the pan 20 minutes before turning out onto a wire rack to cool completely.
Store bread at room temperature for up to 2 days, or in the fridge for up to 5 days.
Calories: 475kcal, Carbohydrates: 56g, Protein: 7g, Fat: 25g, Saturated Fat: 11g, Cholesterol: 58mg, Sodium: 134mg, Potassium: 394mg, Fiber: 4g, Sugar: 30g, Vitamin A: 355IU, Vitamin C: 2mg, Calcium: 87mg, Iron: 3mg