Preheat oven to 350 degrees. Spray two 8x4" loaf pans with Baker's Joy (or use shortening and flour), and line the bottom with parchment paper.
In a large mixing bowl, whisk together the oil and sugars till smooth. Whisk in eggs, zucchini, buttermilk, and vanilla till well blended.
In small mixing bowl, combine flour, baking soda, salt, cinnamon, cocoa, and chocolate chips. Add to wet ingredients and stir just till blended.
Spread batter into the prepared loaf pans. Combine topping ingredients in a small bowl, and sprinkle evenly over the top of the batter.
Bake at 350° for 55-60 minutes, or until a toothpick inserted in the middle comes out clean.
Let cool in pan for 10 minutes, then carefully remove to a wire rack to cool completely.
To make muffins, spoon batter into well greased muffin pans, sprinkle with topping, and bake for about 18 minutes.
For mini loaves, divide batter between six mini loaves and bake for about 30 minutes.