If using Healthy Italian Breadsticks or Pizza Crust for the crust, wait until the crusts have baked for 20 minutes and then add and arrange all of the toppings (if using a different pizza crust, then follow the directions for that pizza crust).
Spread sauce over pizza dough. Sprinkle cheese all over sauce. Arrange zucchini, tomatoes, and yellow squash over pizza. Scatter onion and bell pepper over vegetables. Sprinkle with red pepper flakes, if desired, and season with salt and pepper.
Put the pizza back in the oven to cook for about 10 more minutes.