Preheat your oven to 350°F (176°C). Grease a 9x5-inch loaf pan with olive oil or butter.

In a medium bowl, whisk together all-purpose flour, cocoa powder, baking soda, salt, and espresso powder until combined.

In a separate large bowl, combine olive oil, brown sugar, and granulated sugar. Mix until smooth and creamy.

Add the eggs one at a time, mixing until incorporated. Blend in vanilla extract and sour cream.

Mash the ripe bananas in a small bowl and gently fold them into the wet ingredients.

Gradually fold the dry ingredients into the wet mixture, mixing just until combined.

Toss the dark chocolate chips and semi-sweet chocolate chips with a tablespoon of flour. Gently fold them into the batter.

Pour the batter into the prepared loaf pan. Smooth the top with a spatula and sprinkle reserved chocolate chips on top.

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

Once baked, cool in the pan for 20 minutes, then transfer to a wire rack to cool completely before slicing.