Meanwhile, in a small saucepan over medium heat, stir together milk, pumpkin puree, 1 teaspoon caramel sauce, cocoa and brown sugar. Heat, stirring often, until warm but not boiling, and sugar is melted. Remove from heat.
Place one cup of hot coffee in each of the two mugs. Evenly pour pumpkin mixture between each cup, leaving about ⅔ of space from the top, and stir.
Garnish with whipped cream, a sprinkle of pumpkin spice and drizzle with caramel sauce.