here is the uncensored truth.
you start with a ball of dough the same as all the other balls of dough for the respective pizza sizes. after the dough has risen at least to the minimum level, you prepare a square pizza pan of somewhat smaller area than the respective size round pizza by squirting about a cup of partially hydrogenated garlic butter sauce into the pan. you then take the pizza dough and press it into the square garlic butter soup to fill the pan. next you brush the top of the dough with more garlic butter sauce and put it in the fridge for at least 24 hours to absorb it all.
then you sauce, cheese, top and cook to order!
what a special process! I think pizza hut is somewhat similar but i cannot confirm.