In a medium-sized saucepan, combine the milk, white chocolate and vanilla.
Stir over medium heat until the chocolate has melted and the mixture is just simmering, 3-5 minutes. Remove from the heat and stir in any optional add-ins, if using.
Pour into mugs and top with whipped cream or mini marshmallows, if desired. Serve immediately.
Peppermint extract is very strong, so go light at first. I’d start with 1/4 teaspoon and add more if desired, 1/8 - 1/4 teaspoon at a time. You can go heavier on the alcohol (around 2 tablespoons). I like adding liqueurs such as Rumchata, Baileys, Grand Marnier or Kahlua. You could also try adding a splash of spiced rum!