Preheat the oven: Preheat your oven to 350°F (175°C). Grease or line a 4×8-inch (10×20 cm) loaf pan with parchment paper so the bread releases easily after baking.

Mix the dry ingredients: In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until everything is evenly combined. Set aside.

Combine the wet ingredients: In a large mixing bowl, mash the ripe bananas; it’s okay if there are still a few small banana lumps.  Then stir in the oat milk and vanilla extract.

Add sugar and oil: Whisk in the light brown sugar and neutral oil until smooth.

Add cocoa powder: Whisk in the cocoa powder until the mixture looks rich and smooth.

Bring it all together: Add the dry flour mixture to the wet ingredients and gently stir until just combined and with no dry streaks remaining. Do not overmix or the bread can turn out dense.

Fold in chocolate chunks: Gently fold in the dark chocolate chunks or vegan chocolate chips for gooey bites throughout.

Fill the pan: Scrape the batter into the prepared loaf pan, smoothing the top.

Bake the bread: Bake for 55–65 minutes, or until a skewer inserted in the center comes out clean.