Preheat oven to 400°F (200°C).

Grease a baking sheet and sprinkle with cornmeal.

Unroll pizza crust and shape into a 12-inch square.

Place shaped crust on the prepared baking sheet.

Brush the crust with 1 teaspoon of olive oil.

Arrange 9 slices of mozzarella cheese over the dough, leaving a 1-inch border.

Cut the remaining cheese slices into quarters and set aside.

Place half of the zucchini slices around the edges of the cheese, about 2 inches apart.

Fold the edges of the dough over the zucchini, about 1 inch.

Bake for 6 minutes.

Layer the onions and remaining zucchini on top of the cheese.

Top with the tomato slices.

Sprinkle with salt and pepper.

Bake for 16 minutes, or until the crust is golden brown.

Arrange the reserved cheese pieces over the tomatoes.

Bake for 4 minutes longer, or until the cheese is melted.

Drizzle with the remaining olive oil.

Sprinkle with fresh basil.

Let stand for 10 minutes before slicing and serving.