In this paper we deal with an inverse electromagnetic casting problem, which consists in designing a set of inductors in such a way that a liquid metal achieves a given shape. The inductors are assumed to be made of single solid-core wires with a negligible cross-section area. The inverse problem is rewritten in the form of an optimization problem. In particular, a Kohn-Vogelius based functional is minimized with respect to a set of admissible inductors, leading to a non-iterative second order optimization algorithm. Finally, several numerical examples are presented showing that the proposed approach is effective to design suitable inductors.