Preheat oven to 350°. Grease a 13x9-in. baking pan.
In a large bowl, whisk the first 7 ingredients. In another bowl, whisk eggs, yogurt, oil & vanilla until blended. Add to flour mixture; stir just until moistened. Stir in zucchini.
Transfer batter to prepared pan. Bake 25-30 minutes or until top springs back when lightly touched.
Cool completely in pan on a wire rack. If desired, dust with confectioner’s sugar before serving.