In a medium saucepan, combine 1 cup of milk with the white chocolate chips and cocoa powder. Cook over medium heat, whisking periodically, until the chocolate is melted and combined.
Stir in the pumpkin puree and pumpkin pie spice. Continue to cook while occasionally stirring until heated through.
Add the remaining milk and cook until heated through.
Portion into coffee mugs. Serve warm with topped with whipped cream, white chocolate shavings, and/or nutmeg.
Notes
If using freshly roasted pumpkin instead of canned pumpkin, I recommend pouring the hot chocolate through a fine mesh sieve to eliminate any chunks. Canned pumpkin is much smoother.
Nutritional information does not include toppings.