Preheat oven to 325 degrees F. Coat a 4" x 8" loaf pan with cooking spray.
Measure flour blend and cocoa powder by lightly spooning into measuring cup and then leveling off with the back of a knife. In a medium bowl, combine the flour blend, sugar, cocoa powder, salt, and baking soda.
In a large bowl, lightly beat the egg. Stir in the zucchini, oil, milk, and vanilla. Add the flour mixture and chocolate chips and blend until smooth.
Pour batter into prepared loaf pan and bake 60 minutes, or until the middle of the top of the loaf springs back when lightly touched.
Cool completely in pan and then turn out and slice.