05In a small pot over medium heat combine the reserved pineapple juice and 1/4 cup of water. Add the brown sugar and butter and bring to a simmer. Add the remaining 3 pineapple rings and saute for 4 minutes or until the sauce thickens slightly. Remove from the heat. Reserve.06To serve, remove the pound cake from the pan and transfer it to a serving plate. Arrange pineapple rings on top and secure with toothpicks, if necessary. Pour the sauce over the cake and serve.