Prep the pan and oven. Heat the oven to 350°F (175°C). Line a 9x5-inch loaf pan with parchment and lightly grease the sides.

Mash the bananas. In a large bowl, mash the bananas until mostly smooth with a few small lumps. You should have about 1 1/3 cups.

Whisk in wet ingredients. Add eggs, oil, brown sugar, granulated sugar, and vanilla. Whisk until the mixture looks glossy and well combined.

Bloom the cocoa. In a separate small bowl, stir cocoa with the hot coffee or hot milk until smooth and dark. This step intensifies the chocolate flavor.

Combine wet base. Stir the bloomed cocoa into the banana mixture until evenly blended.

Mix dry ingredients. In another bowl, whisk flour, baking soda, baking powder, and salt until uniform.

Bring it together. Add the dry ingredients to the wet and fold gently with a spatula. Stop when just a few flour streaks remain.

Add chocolate chips. Fold in the chocolate chips (and nuts, if using). Do not overmix—the batter should be thick and lush.

Fill the pan. Scrape the batter into the prepared loaf pan, smoothing the top. Sprinkle a handful of chocolate chips over the surface for a bakery-style look.

Bake. Bake for 55–70 minutes. Start checking at 55 minutes. A tester should come out with moist crumbs, not wet batter. If the top browns too fast, tent loosely with foil.

Cool for best texture. Let the bread cool in the pan for 15 minutes, then lift it out to a rack to cool completely. For a clean slice and fudgy crumb, wait at least 1 hour before cutting.