1Heat oven to 350°F. Grease bottom only of 8-inch or 9-inch square pan with shortening or cooking spray.
2Reserve 1/4 cup cake mix for streusel; set aside. In large bowl, beat remaining cake mix, 1/2 cup butter, zucchini, cinnamon, cloves, water and eggs on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Spread in pan.
3In small bowl, mix reserved 1/4 cup cake mix and streusel ingredients with fork until mixture is crumbly. Sprinkle over batter.
4Bake 44 to 49 minutes for 8-inch pan or 38 to 43 minutes for 9-inch pan until toothpick inserted in center comes out clean. Serve warm or cool.