Preheat your oven to 350°F (175°C) and grease a loaf pan with butter or cooking spray.
In a medium bowl, combine the all-purpose flour, cocoa powder, baking soda, and salt. Whisk them together until well-mixed and set aside.
In a separate large bowl, mix the granulated sugar, brown sugar, and olive oil until smooth.
Add in the eggs one at a time, followed by the vanilla extract. Beat until well combined.
Gradually add the dry mixture to the wet ingredients, alternating with the buttermilk. Mix until smooth, being careful not to overmix.
If desired, fold in the chocolate chips to add an extra layer of chocolate goodness.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted in the center comes out clean.
Allow the cake to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.