1Heat oven to 350°F. Grease bottom and sides of 9- or 8-inch square pan. In large bowl, mix brown sugar, butter, vanilla and egg. Stir in flour, baking soda, cinnamon and 1/2 teaspoon cloves. Stir in zucchini and nuts. Spread in pan.
2Bake 25 to 30 minutes or until toothpick inserted in center comes out clean. Cool completely, about 1 hour.
3In medium bowl, mix all frosting ingredients until smooth and spreadable. Spread frosting over bars. For bars, cut into 6 rows by 4 rows.