Instructions

• Preheat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan with nonstick baking spray and set it aside.
• In a medium bowl, whisk together 1 cup all-purpose flour, 1/2 cup unsweetened cocoa powder, 2 teaspoons baking powder, and 1/2 teaspoon sea salt until evenly combined. (If you prefer, you can sift these ingredients together.) Set the dry mixture aside.
• In a large bowl, mash the bananas with a fork until you have 1 1/2 cups mashed bananas and no large chunks remain.
• Add the slightly cooled melted 1/4 cup unsalted butter, 1/4 cup canola oil, 1 teaspoon vanilla extract, and 1 large room-temperature egg to the mashed bananas. Stir until the mixture is evenly combined.
• Stir in 1 cup packed light brown sugar to the banana mixture until smooth.
• Add the dry ingredients to the wet ingredients and gently fold with a spatula until just combined. Do not overmix.
• Stir in 3/4 cup of the 1 cup large semisweet chocolate chips and 1/2 cup chopped walnuts, if using, until evenly distributed.
• Transfer the batter to the prepared loaf pan and smooth the top with a spatula. Sprinkle the remaining 1/4 cup chocolate chips evenly over the top.
• Bake for 50–60 minutes, starting to check at 50 minutes. The bread is done when a toothpick inserted into the center comes out mostly clean with no raw batter (a few moist crumbs are fine). If it needs more time, continue baking and check every 5 minutes.
• Remove the pan from the oven and set it on a wire cooling rack. Let the bread cool in the pan for 15 minutes, then turn it out onto the rack. Cool until it is cool enough to slice, then cut into slices and serve.