Chocolate Banana Bread

Name: Chocolate Banana Bread
Ingredients: 2 to 3 medium ripe bananas (about 400 g after peeling); 2 large egg; 2 tablespoons milk (any type); 2 teaspoons vanilla extract; 1 teaspoon espresso powder (optional but recommended); 1/2 cup unsalted butter, melted (115 g or 1 stick); 3/4 cup packed brown sugar (165 g); 1 teaspoon baking powder; 1 teaspoon baking soda; 1/2 teaspoon kosher salt; 2 cups all-purpose flour (280 g); 1/4 cup natural cocoa powder (unsweetened, not Dutch-process, 30 g (see section above)); 3/4 cup chocolate chips (135 g (see section above for other options))