Use a skewer or fork to pierce the cooled cake all over before applying the rum syrup, allowing the liquid to penetrate deeply for maximum flavor absorption throughout every layer.

Pour the rum syrup while it's still warm over the cooled cake—the heat helps the cake absorb the liquid more efficiently than cold syrup, intensifying the rum flavor.

Choose a quality dark rum with molasses notes (like Myers's or Bacardi 151) rather than cheap varieties; the complex spiced undertones will elevate your cake and balance the sweetness of the pudding and cake mix.

The instant vanilla pudding in the batter acts as a humectant that keeps the cake moist for days; don't skip it even though you're using cake mix, as it prevents drying despite the alcohol content.

Wrap the soaked cake and let it sit overnight before serving—this allows the rum to fully integrate with the cake's crumb structure and develop deeper, more sophisticated flavor complexity.