Grab a substantially-sized bowl, and in it, cream together your sugars and cannabis-infused butter, until the contents transform into an airy, almost fluffy mixture.
When that happens, beat in your cinnamon, nutmeg, and ice cream.
Then, when all of those elements are fully intertwined with one another, cover up that bowl, and toss it in the freezer.
Next, grab a heat-friendly glass (preferably a mug), and toss in ½ cup’s worth of that previously-made butter mixture. After that, pour in your boiling water, and stir up the contents, until everything completely dissolves.
Then, top everything off with your desired amount of rum. Again, stir everything together, and boom, that’s how you make Cannabis-Infused Hot Buttered Rum!