Even though I’ve heard that floating dark rum on top isn’t part of the original Mai Thai recipe, I think it’s a fun and pretty addition! You can choose if you want to do it or not. To float the dark rum on top, gently pour the rum onto the top of the ice. It will float! Tip: To help the rum pour gently and slowly, you can hold a spoon upside down over the ice and pour the rum onto the spoon, letting it flow into the glass on the ice.