1 lb. softened butter
1 lb. light brown sugar
1 lb. confectioners' sugar
Dark rum
1 tbsp. cinnamon
1 tbsp. nutmeg
1 qt. vanilla ice cream, softened

In a large bowl, mix until smooth the butter, brown sugar, confectioners' sugar, cinnamon, and nutmeg. Add vanilla ice cream and mix well. Keep frozen. I suggest using a plastic container for storing in the freezer - 1/2 gallon size perhaps the type in which ice cream is packaged.

For each cup of hot buttered rum, place in mug: 2 tablespoons of frozen mixture with 1 shot of dark rum. Fill mug with boiling water and stir.