This recipe by Delish actually comprises of two parts, also, you’ll have to make the hot buttered rum so make sure you prepare it in advance!
Hot Buttered Rum
Make the Buttered Rum Batter: In a mixing bowl, beat butter and brown sugar until light and fluffy. Beat in ice cream and cinnamon, then spoon into a large mason jar or Tupperware container. Store in freezer until mostly hardened, about 2 hours (or store there until you’re ready to serve drinks).
Make the Drinks: In a large saucepan, heat cider until boiling, stirring occasionally. Remove from heat and pour into a pitcher or easy-to-serve container.
Place about 2 tbsp of the buttered rum batter into each mug. Fill about 1/3 of the way up with rum, then top with hot apple cider. Stir and serve.