Preheat the oven to 350°F (175°C). Grease and flour a 9×5-inch loaf pan.
In a large bowl, sift together the all-purpose flour, unsweetened cocoa powder, baking powder, baking soda, and salt.
In a separate medium bowl, whisk together the granulated sugar, vegetable oil, eggs, and vanilla extract until smooth.
Add the buttermilk to the wet ingredients and mix until combined.
Gradually add the dry ingredients to the wet ingredients, stirring gently until just combined. Do not overmix.
Fold in the semi-sweet chocolate chips evenly into the batter.
Pour the batter into the prepared loaf pan and spread it evenly.
Bake in the preheated oven for 45 to 50 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.
Remove the loaf from the oven and allow it to cool in the pan for 10 minutes.
Transfer the loaf to a wire rack to cool completely before slicing.