Preheat your oven to 350°F (175°C). Grease a 9×5-inch loaf pan and line with parchment paper leaving a little overhang on the long sides so you can lift the loaf out later.
In a large bowl, sift together 1¾ cups of flour, ½ cup of cocoa powder, 1 teaspoon of baking soda, ½ teaspoon of baking powder, and ½ teaspoon of salt. Whisk to fully combine.
Add ¾ cup of light brown sugar, ½ cup of granulated sugar, ½ cup of vegetable oil, 2 eggs, 1 teaspoon of vanilla and 1 cup of buttermilk to a bowl. Whisk until smooth.
Pour the wet ingredients into the dry and stir gently until just combined, don’t overmix. Pour in ½ cup of hot coffee or hot water and fold gently. The batter will be fairly loose, like a thick brownie batter, that’s what keeps it moist.
Fold in ¾ cup of chocolate chips if you want extra pockets of melty chocolate.
Pour the batter into the prepared loaf pan and smooth the top. Bake for 50 minutes, or until a toothpick inserted into the center comes out mostly clean with a few moist crumbs. Don’t open the oven too early, set it and forget it for the best rise and minimal cracking.
Let the loaf cool in the pan for 15 minutes, then use the parchment overhang to lift it out and cool completely on a rack.
In a microwave-safe bowl, combine ½ cup of chocolate chips, 2 tablespoons of cream or milk, and 1 tablespoon of butter. Microwave in 30-second bursts, stirring between each, until smooth. Pour over the cooled loaf.
Slice and enjoy. It’s rich, moist, and stays tender for days.