Set a pizza stone or baking sheet on the bottom rack of the oven and preheat to 500 degrees F. Toss the zucchini with 1/4 teaspoon salt in a medium bowl and let sit.
Spray the bottom of a 9-by-13-inch metal pan with cooking spray. Place the dough on a lightly floured surface and start pressing it into a rectangular shape. Transfer the dough to the prepared pan and press it evenly all the way to the edges. Place the pan on the hot pizza stone and partially bake for about 10 minutes. The bottom should be lightly golden brown and crisp.
Remove the pan from the oven. Sprinkle the crust with the mozzarella in an even layer. Pat-dry the zucchini and shingle the rounds in a single layer over the mozzarella. Spray the cherry tomatoes with cooking spray and toss with 1/4 teaspoon salt in a small bowl, then top the zucchini layer with the tomatoes, olives and feta. Drizzle all over with the olive oil.
Return the pizza to the oven and bake until the bottom is deep golden brown and the cherry tomatoes have wilted, 18 to 20 minutes.
Top with torn basil leaves. Cut into 8 squares.