Stars are born from the gravitational collapse of molecular clouds, which are the coldest, densest regions of the interstellar medium (ISM). The primary drivers of ionization in molecular clouds are cosmic rays (CRs), charged particles accelerated to relativistic velocities by high energy shocks. Despite their potential impacts on gas dynamics and chemistry, no previous simulations of star cluster formation have included explicit CR transport to date. I recently conducted the first numerical simulations following the collapse of a 2000 solar mass molecular cloud and the subsequent star formation including CR transport. These simulations were run on the supercomputers at the Texas Advanced Computing Center (TACC) using the STAR FORmation in Gaseous Environments (STARFORGE) framework implemented in the GIZMO code. In this talk I will review the results of these simulations, including how the CRs are transported through the cloud and the impacts on the star-forming properties of the cloud. I will explain how these results depend on the CR energy density and transport physics, and compare the results to indirect measurements of CR ionization in molecular clouds. Throughout this discussion I will highlight the use of high-performance computing resources critical for completing this study. Finally, I will discuss ongoing simulations following the collapse of a 20000 solar mass cloud, which will allow us to assess the impact of CRs on the stellar initial mass function (IMF).
