Preheat the oven to 350°F.

Grease a 9-by-5-inch loaf pan with nonstick baking spray. Take a strip of parchment paper and fold so that it's as wide as the pan, but goes up and slightly over the ends to provide handles.

In a medium bowl sift together flour, cocoa powder, baking powder, and sea salt.

In a large bowl, mash the ripe bananas with a fork until no large chunks are left. Add the slightly cooled melted butter, oil, vanilla, and eggs. Stir until fully combined.

Whisk in brown sugar until smooth.

Add the dry ingredients to the wet ingredients, and gently fold in with a spatula, careful not to overmix.

Stir in 3/4 cup of the chocolate chips and the chopped walnuts.

Transfer batter into the prepared pan and sprinkle the remaining 1/4 cup of chocolate chips on top of the bread and a 1/4 cup of the walnut pieces.

Bake for 50-60 minutes, or until a toothpick inserted into the center of the bread comes out mostly clean, with no raw batter on it. Start checking on the bread at the 50-minute mark, and if still needs to bake more, check on it every 5 minutes.

Once fully baked, remove the pan from the oven and set it on a wire cooling rack. Let the bread cool in the pan for 15 minutes.

For easy removal, run a knife around the side edges of the bread and gently remove it from the pan by pulling up on the parchment "handles."

Let finish cooling, slice, and devour!