Chocolate Buttermilk Zucchini Cake

1 cup brown sugar
1/2 cup sugar
1/2 cup butter
1/2 cup oil
3 eggs
1 tsp vanilla
1 cup buttermilk
2 1/2 cups flour
1 tsp cinnamon
2 tsp baking soda
4 Tbl. cocoa
2 cup grated zucchini
chocolate chips (I used 1/2 semi-sweet and 1/2 milk)
whipped topping (optional)

     In a large bowl, cream together sugars, butter, and oil.  Mix in eggs, vanilla, and buttermilk.
     In a separate bowl, mix together flour, cinnamon, baking soda and cocoa.  Add to creamed mixture.  Stir in zucchini.  Mix until all ingredients are well combined.
     Pour into a greased 9x13 pan.  Sprinkle top with choco chips.  Bake at 325 for 45 minutes.  Turn off oven and let cake cool inside.  The cake will be very moist.  Serve with whipped topping.