Remove the pan from the oven and use a skewer to pierce the cake all the way down to the bottom in several places. Slowly pour the rum syrup over the surface of the cake. Let the cake cool for about 5 minutes in the pan and then gently transfer it, right side up, to a wire rack to cool completely. Wrap it tightly in plastic wrap and let it rest overnight before slicing since the flavor of the cake matures with time. Originally published December 10, 2010.