Prepare the oven and pan:
Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.
Mix dry ingredients:
In a medium bowl, whisk together flour, cocoa powder, baking soda, baking powder, salt, and espresso powder. Set aside.
Combine wet ingredients:
In a large mixing bowl, whisk together eggs, granulated sugar, brown sugar, vegetable oil, Greek yogurt, and vanilla extract until smooth.
Incorporate zucchini:
Gently fold the shredded zucchini into the wet ingredients.
Combine wet and dry mixtures:
Gradually add the dry ingredients to the wet mixture, stirring until just combined. Avoid overmixing.
Add chocolate chips:
Fold in the chocolate chips, reserving a few for sprinkling on top if desired.
Bake:
Pour the batter into the prepared loaf pan. Smooth the top and sprinkle with reserved chocolate chips. Bake for 50–60 minutes or until a toothpick inserted in the center comes out clean.
Cool:
Allow the bread to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.