St Louis Style Pizza: this is a thin crust variation of the Chicago Style pizza. A major difference is the type of cheese used. This pizza uses Provel cheese instead of the Mozzarella cheese used on the Chicago style. Sausage and hamburger are normally formed into balls instead of scrambled and other toppings are usually sliced instead of diced. The crust is similar to a cracker in its crunch and the pizza is normally cut into small squares.