Recipe from Matthew Greenleaf of Ky.
Preheat oven to 350' F. In a large mixing bowl, combine butter, oil and sugar; beat. Then add eggs and vanilla. Combine dry ingredients and add to creamed mixture alternately with buttermilk. Mix well. Stir in zucchini. Pour into greased 13x9 inch pan. Sprinkle with chocolate chips. Bake 40-45 minutes, or until toothpick inserted into center comes out clean.