Chocolate Zucchini Cake

2 1/2 c. flour
1/4 c. cocoa
1 tsp. baking soda
1 tsp. salt
1 tsp. vanilla
1/2 c. butter or margarine
1/2 c. oil
1 3/4 c. white sugar
2 eggs
1/2 c. buttermilk
2 c. grated unpeeled zucchini
6 oz. chocolate chips
3/4 c. chopped nuts (optional)

Mix sugar and butter; add oil and eggs and beat well. Add buttermilk and cocoa and mix well and completely dissolve cocoa. Add rest of dry and wet ingredients but chocolate chips, mix well. Pour into floured and greased 9 X 13 pan or larger. Sprinkle chocolate chips on top. Bake at 325 degrees for 55 minutes. Serve warm without frosting and with ice cream or sprinkle with powdered sugar.