A fuel cell assembly including a fuel reforming unit for reforming a fuel supply for a series of fuel cells constituting a fuel cell stack. The reformed fuel supply is routed first to the anode of the fuel cell most adjacent the reforming unit, and thereafter to a manifold external to the stack. The manifold intakes that portion of the reformed fuel supply not fully exhausted after passing through the first anode and feeds such reformed fuel to successive fuel cells in series, thus providing staged fuel supply throughout the stack and optimal fuel utilization in producing electricity. The reforming unit includes a series of baffles for directing the reformed fuel supply to the first anode and to the manifold to maximize utilization of fuel consumed by cells in the stack. Also, cooling occurring as a result of the endothermic reaction occurring in the reforming unit is captured and spread optimally throughout the stack to achieve optimal temperature gradients throughout the stack, thus enabling optimal operation of and increased life of the stack.