Heat a grill on high; spray grates with cooking spray. Flour a cookie sheet, and pull off a grapefruit sized amount of dough. Sprinkle dough with flour. Initially flatten using hands, then use a rolling pin to roll out to about 1/3″ thickness. Shake your cookie sheet to make sure that the dough can easily slide around. If not, loosen, and add a bit more more flour under dough using a long spatula turner. Spread with pesto, and top with zucchini and then cheeses. Using a knife or pastry brush, brush garlic bread topping along the crust.