In this paper we consider the simultaneous optimization of the controller and plant in a one degree-of-freedom system. In particular we are interested in optimal trajectories between fixed points connected by heteroclinic orbits. We find that designing the plant dynamics to have a heteroclinic connection between target states enables a low energy transfer between the states. We use a nested optimization strategy to find the optimal plant dynamics and control effort for the transition. Additionally, we uncover plant optimality conditions which reduce the complexity of the optimization. Published by Elsevier Ltd