Preheat your oven to 350°F (175°C) and grease a standard loaf pan with olive oil or butter.

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

In another bowl, cream together the olive oil, brown sugar, and granulated sugar until light and fluffy, then add the eggs one at a time.

Mash the ripe bananas and fold into the wet mixture.

Gradually add the dry ingredients to the wet mixture and mix until just combined.

Fold in the dark and semi-sweet chocolate chips, reserving a handful for later.

Pour the batter into the prepared loaf pan and smooth the top, optionally adding banana slices.

Bake in the preheated oven for 55-65 minutes or until a toothpick inserted comes out clean.

Allow to cool in the pan for about 20 minutes before transferring to a wire rack to cool completely.