It is easy to make square burgers, take a small baking sheet and press your burger into it. Use a larger sheet pan and press down on top to flatten and pack the burger. Use some parchment paper top and bottom for ease of handling. Pull the pressed rectangle out of the pan, slice it by pushing straight down with a knife(this will seal the edges of the patties so they don't come apart). Mom did this all the time, fastest way to make burgers for a family of 7!