Preheat oven to 350 degrees. Grease two 8×4 inch loaf pans, or one 9×5 pan.
In a large bowl, combine flour, cocoa powder, baking soda and salt.
In another large bowl, combine sugars, eggs, melted butter and vanilla
Add the flour mixture to the sugar/butter mixture and stir to combine. Do not over mix.
Fold in grated zucchini and 1 cup of chocolate chips.
Spread batter in prepared loaf pans and sprinkle remaining chocolate chips over top
Bake for 40-60 minutes (depending on size) or until an inserted knife comes out clean. If necessary, cover with foil during the last 10-15 minutes of baking to prevent over-browning.