01 -
Preheat the oven to 325°F. Line a light-colored metal 8 1/2 by 4 1/2-inch loaf pan with a sheet of parchment paper, leaving an overhang, then spray with nonstick cooking spray.
02 -
In a large bowl, whisk together the flour, cocoa powder, sugar, baking soda, and salt.
03 -
In a medium bowl, whisk together the eggs, sour cream, oil, and vanilla until thoroughly combined.
04 -
Make a well in the center of the dry ingredients and stir the wet ingredients in with a rubber spatula until just combined. Fold in the zucchini and chocolate chips, reserving some to sprinkle on top.
05 -
Pour batter into prepared pan, smoothing the top. Sprinkle with reserved chocolate chips.
06 -
Bake for about 70 minutes or until a digital thermometer registers at least 200°F. Alternatively, check that a toothpick inserted in the center comes out clean with just a few crumbs attached. Melted chocolate chips may resemble uncooked batter.
07 -
Let the loaf cool in the baking pan on a wire rack for 15 minutes before removing to a wire rack to cool completely.