Prepare a tall glass full of ice and add the vanilla rum. Next add the regular old rum, which you need to kick that alcohol concentration back up to an acceptable level. Next add the vanilla cola. Note: do not add Coca-Cola's Cherry-Vanilla cola, as the drink will taste like ass.

You may stir, but experts agree that the carbonation in a properly-poured cola will sufficiently mix your drink. If it doesn't all the way, it's actually a nice way to break your way into the rum-heavy nether-regions of your glass.

This drink best served quickly and with a backup to follow.

(VBAC? Google it.)