Melanie's Delicious Chocolate Zucchini Cake

Per recommendations on Sunday night, here is the recipe for Mel's fabulous cake. I didn't totally do it in Melanie fashion as I did use Pillsbury Fudge Chocolate frosting. Anyone have an amazing chocolate frosting recipe to share?

1/2 c. softened butter
1/2 c. oil
2 eggs
1/2 c. sour milk
1 tsp vanilla
1 3/4 c. sugar
2 1/2 c. flour
4 TBSP cocoa
1/2 tsp bkg pwdr
1 tsp bkg soda
1/2 tsp cinnamon
1/2 tsp cloves
2 c. finely grated zucchini
3/4 c. chocolate chips

Cream first 2 ingredients. Add eggs, vanilla, milk; beat well. Mix dry ingredients add (beat well). Stir in zucchini and 1/4 c. chocolate chips. Pour in greased 9x13 pan. Sprinkle 1/2 c. chocolate chips on top of batter. Bake at 325 for 40-45 minutes.