Preheat your oven to 350°F (175°C). Grease a standard loaf pan with butter or cooking spray to prevent sticking.
In a large mixing bowl, whisk together: 1 cup granulated sugar, 1½ cups all-purpose flour, ½ cup cocoa powder, 1 tsp baking soda, and ½ tsp salt until well combined.
In another bowl, mix the wet ingredients: 1 cup buttermilk, ½ cup vegetable oil, 2 large eggs, and 1 tsp vanilla extract. Ensure the mixture is well combined for even distribution of flavors.
Now combine the wet and dry ingredients: Gradually pour the wet mixture into the dry ingredients, stirring gently until just combined. It's vital not to overmix; a few lumps are fine.
Fold in: 1 cup chopped pecans and ½ cup dark chocolate chips. Use a spatula to incorporate them evenly into the batter without overworking it.
Pour the batter into the prepared loaf pan. Use a spatula to smooth out the top for an even bake.
Bake in the preheated oven for 55-60 minutes. To check for doneness, insert a toothpick into the center of the loaf. It should come out clean or with just a few moist crumbs.
Once baked, remove the loaf from the oven and let it cool in the pan for 10 minutes. Then transfer it to a wire rack to cool completely.
While the loaf is cooling, prepare the ganache: Heat ½ cup heavy cream in a small saucepan until just simmering, then pour it over ½ cup chopped dark chocolate in a bowl. Allow it to sit for a couple of minutes, then stir until smooth and glossy.
Drizzle the ganache over the cooled loaf. Let it set for a bit before slicing to let the chocolate firm up slightly for a beautiful finish.