It is well known that stars observed in the local Universe form with something very close to a universal initial mass function (IMF) where the vast majority are of low mass. However, theory and simulations of the formation of the first stars in the Universe predict a top-heavy IMF with significant dependence on environment. How and when does this transition occur? This has been studied extensively with simplistic models of collapsing gas and highly idealized 3D simulations, but few works have attempted to simulate the formation of the first low mass stars within a cosmological context. I will present a series of simulations that begin with cosmological initial conditions and end with the collapse and fragmentation of metal-enriched gas on scales of a few hundred AU. With these simulations, we are able to study the physical conditions in which the oldest stars observed formed as well as the means by which star-forming gas was first enriched with metals.