Pre-Heat oven to 350 line a 8 x 8 pan with aluminum foil, leaving extra fold over 2 opposite edges to use as handles after the cake is baked. Coat the foil with cooking spray in large bowl, combine flour, baking powder, baking soda, cinnamon and salt. In medium bowl, with a wire whisk, beat eggs, brown sugar, yogurt, oil and vanilla extract until smooth. Stir in the Zucchini and chocolate chips. Add the zuchinni mixture to the flour mixture and stir just until blended. Scrape into the prepared pan. Bake 40 minutes or until the cake is springy to the touch and a wooden pick inserted in the center comes out clean. Let the cake cool in the pan on a rack for 30 minutes. Remove from the pan using the foil handles discard the foil and cool completely on the rack
