Preheat the oven to 325°F. Lightly grease a 9" x 13" pan.
In a large mixing bowl, beat together the butter, oil, sugar, vanilla, baking soda, baking powder, and salt until smooth.
Beat in the eggs.
In a small bowl, combine buttermilk and coffee.
Add the buttermilk mixture to the butter mixture alternating with the flour.
Add the cocoa mixing until smooth.
Fold in the zucchini and chocolate chips and then pour batter into pan.
Bake the cake for 30 to 35 minutes, until the top springs back lightly when touched, or center no longer appears wet.