Preheat oven to 350°F.
In a medium bowl, stir together the sugar, eggs, vanilla, and vegetable oil.
Add in flour, cocoa powder, baking soda, and baking powder. Mix well.
Fold in the zucchini until it is evenly distributed.
Pour mixture into a prepared 9x13-inch pan.
Bake 40-50 minutes (or until a clean toothpick comes out with a few crumbs, but not wet batter).
Remove the cake from the oven, pierce with a fork, and drizzle about 1/2 cup of chocolate simple syrup over the top.
Allow cake time to set before serving.