Chocolate Zucchini Cake

1/4 tsp baking powder
2 tsp baking soda
2 C flour
1 T cinnamon
4 T cocoa, unsweetened
3 eggs
2 C sugar
1 C vegetable oil
1 T vanilla
2 C zucchini, grated
1 C walnuts, optional

Preheat oven to 350 degrees and lightly spray a 9 x 13-inch pan with cooking spray.   Mix all ingredients in a large bowl until well combined, do not overmix. Pour into pan and bake for 50 to 60 minutes or when a toothpick inserted in the middle comes out clean. Cool completely, dust with powdered sugar and serve with whipped cream or ice cream if desired.