Preheat the oven to 350 degrees F. Coat an 8.5 inch or 9 inch loaf pan with cooking spray.
In a large bowl, mix together the 1 1/4 cups flour, cocoa powder, baking soda, salt and cinnamon.
Place the sugar and egg in a medium bowl. Mix until smooth. Add the butter, vegetable oil and vanilla extract; whisk to combine.
Add the zucchini to the wet ingredients and stir until incorporated.
Pour the wet ingredients into the dry ingredients. Stir gently until just combined.
Toss 3/4 cup of the chocolate chips with the teaspoon of flour.
Add the flour coated chocolate chips to the batter and stir until just combined.
Pour the batter into the loaf pan. Sprinkle the remaining chocolate chips over the top.
Bake for 50 to 55 minutes or until a toothpick inserted into the center of the loaf comes out clean, or with just a few crumbs attached.
Remove the pan from the oven. Cool for 15 minutes, then run a thin spatula or knife around the edges of the pan to loosen the bread.
Cool for another 15 minutes, then invert the pan onto a serving plate. Slice and serve.