Preheat the oven to 350°F. Line a muffin tin with liners.
Add the 1 ¼ cup flour, cocoa powder, baking powder, baking soda, and salt together in a medium bowl. Stir well to combine.
Add the egg, brown sugar, vegetable oil, coffee, and yogurt together in a separate bowl. Whisk well to combine.
Pour the wet ingredients into the flour mixture and barely mix together.
Toss the remaining tablespoon of flour in with 1 cup of the chocolate chips. Add the zucchini and chocolate chips into the flour mixture and just barely fold in.
Evenly divide the batter into the muffin tin. They should be about ¾ full. Top with remaining chocolate chips.
Bake for 18 - 20 minutes, to until a toothpick comes out with just a few crumbs clinging to it.
Notes
You can replace the yogurt with buttermilk or sour cream.
Top the muffins with extra chocolate chips for added deliciousness.