This brief presents a novel multiple-input multiple-output (MIMO) control strategy for off-board electric vehicle (EV) DC fast chargers. The proposed feedback matrix design eliminates the need for repetitive controller tuning across multiple interconnected loops while significantly enhancing the performance of interleaved DC buck converters compared to traditional PI/PID controllers. Key advantages of the method include monotonic reference current tracking from any initial state of charge with arbitrarily fast settling time, as well as rapid compensation for load variations and leg imbalance. Numerical simulations demonstrate the improved dynamic response of the proposed discrete-time MIMO algorithm over classical control approaches. Additionally, full-scale hardware-in-the-loop (HIL) testing and scaled-down prototype experiments confirm the practicality and effectiveness of the proposed control strategy.