A sweet, buttery treat to enjoy on a cool evening.
First, we gotta make the batter. In a big pot, melt the butter on medium heat, then blend in both sugars. Take the pot off the heat and whisk in the ice cream, cinnamon, and nutmeg. Pour that stuff into a plastic container, seal it up, and let it freeze in the freezer.
To make the cocktail, measure 1 tablespoon of the batter and 1 fluid ounce of rum into a coffee mug. Fill the mug with boiling water, then stir it. Finish with a little sprinkle of nutmeg on top.
You're gonna end up with a lot of leftover batter, but don't worry! That stuff will keep in the freezer for up to 3 months, so you can use it to make more drinks.