01 - In a medium saucepan over medium heat, combine whole milk and heavy cream. Warm until the mixture is steaming but not boiling.
02 - Add chopped white chocolate to the hot milk mixture. Stir consistently until completely melted and smooth.
03 - Whisk in pumpkin purée, pumpkin pie spice, vanilla extract, granulated sugar, and a pinch of salt. Continue to heat gently, stirring without interruption, until the blend is hot and silky, but avoid boiling.
04 - Taste and refine sweetness or spice according to your preference.
05 - Pour hot cocoa into mugs. Top with whipped cream, a dusting of cinnamon or pumpkin pie spice, and mini marshmallows as desired.