Topology optimization is increasingly used to automate design processes and explore innovative geometries. This study extends this method to motor windings, focusing on coreless electrical machines that allow greater design freedom by eliminating restrictive iron teeth. We optimize the motor winding to maximize the motor constant, balancing torque and Joule losses. We present a versatile design method illustrated by a case study but adaptable to other scenarios. Key contributions include adapting and extending the density-based topology optimization method for motor windings. We introduce a multi-coil interpolation scheme for unrestricted winding pack designs and a 2.5-D topology optimization method that allows spatial overlap of coils, avoiding costly full 3-D analyses. Our approach results in a novel winding topology with tracks of varying width and thickness, achieving up to a 17% increase in the motor constant compared to references.