Chocolate Zucchini Cake

2 1/2 cups flour
1/2 cup margarine
1/2 cup oil
1 3/4 cup sugar
2 eggs
2 cups grated zucchini
1 tsp. vanilla
1/2 cup sour milk (milk + 1 Tblsp. vinegar)
4 Tblsp. cocoa
1/2 tsp. cinnamon
1/2 tsp. salt
1 tsp. baking soda
1 tsp. baking powder

Combine all ingredients. Then, sprinkle with a topping of 3/4 cup of each:
chocolate chips
brown sugar
chopped nuts (optional)

Bake at 350 degrees for 40 to 45 minutes in a greased and floured 9 x 13 inch pan.