Lightly crush the peppercorns, cardamom, cloves and cinnamon, and put in a medium saucepan. Add the ginger, if using. Add 6 cups cold water to the saucepan and bring to a boil over high heat. Remove from the heat and add the tea bags. Let them steep for 5 minutes. Remove the tea bags, and let steep another 10 minutes.
Put the milks and sugar in a medium saucepan and bring to simmer. Strain the tea mixture into the milk mixture and heat through for 1 minute. Whisk the mixture until frothy. Pour the tea into 4 mugs and garnish with cinnamon sticks.