Preheat your oven to 350°F (175°C) and prepare a loaf pan by greasing it well with cooking spray or a light coat of olive oil.

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

In a large mixing bowl, use a hand mixer to blend the olive oil and both sugars until the mixture is smooth and creamy, about 2 minutes. Add the eggs one at a time, mixing well after each addition.

Mix in the vanilla extract and sour cream, followed by the mashed ripe bananas, stirring until fully integrated.

Gradually add the dry ingredient mixture into the wet ingredients, stirring gently until just combined.

Dust the dark chocolate chips in a little extra flour to prevent them from sinking, and then fold them gently into the batter.

Pour the batter into your prepared loaf pan, smoothing the top with a spatula. If desired, sprinkle any reserved chocolate chips on top and add banana slices for garnish.

Place the loaf pan in the preheated oven and bake for 55-65 minutes until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Once baked, remove the bread from the oven and let it cool in the pan for about 20 minutes before transferring it to a wire rack to cool completely.