Place the oven rack at the very top setting and preheat the oven to 450 F (232C) degrees.
Place tomatoes on a sheet pan. Drizzle with olive oil and sprinkle with salt and pepper. Give them a toss. Roast until tomatoes start to burst, 9-10 minutes. Set aside. Do not turn the oven off.
Place a sheet pan or a pizza stone on the top shelf in your oven.
While the tomatoes are roasting make the basil mixture. To do so, place basil, garlic, salt, and pepper in the bowl of a food processor. Pulse a few times to break it into smaller pieces. While the machine is running, drizzle it with olive oil. You may have to scrape the sides with a spatula a few times to turn it into a paste.
Roll the pizza dough into a 14.5-inch circle. Spread it evenly with the basil mixture leaving an inch on the sides. The basil sauce will be a very thin layer. Scatter the roasted tomatoes and mozzarella pieces on top. Lightly brush the sides with olive oil.
Using a pizza peel or the back of a sheet pan, carefully slide the pizza onto the preheated sheet pan or pizza stone. Bake 12-14 minutes or until the cheese is totally melted and the sides turned golden brown.
Remove from the oven and sprinkle it with fresh basil. Let it rest for a few minutes, cut into 8 slices, drizzle with the balsamic reduction (if using), and enjoy.