Preheat your oven to 325°F (163°C) and adjust the oven rack to the lower-middle position.

Grease a 9 x 5-inch loaf pan with butter or oil, and line with parchment paper for easier removal.

Sift together the all-purpose flour, Dutch-processed cocoa powder, baking powder, and salt in a medium bowl.

In a separate bowl, dissolve the instant coffee or espresso powder in buttermilk and set aside.

Cream softened unsalted butter until creamy, then gradually add granulated sugar and mix until light and fluffy.

Add eggs one at a time, mixing for about 20 seconds between each addition.

Gently mix in the buttermilk-coffee mixture and vanilla extract until combined.

Gradually fold in the dry ingredients until just combined, being careful not to overmix.

Pour the batter into the prepared pan and bake for 50-55 minutes, checking doneness with a toothpick.

Once baked, cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.

For ganache, heat heavy cream, pour over chocolate chips, add vegetable oil, and whisk until smooth; drizzle over cake.