Combine sugar, flour, cocoa powder, salt, and spices in a medium-size saucepan. Stir in the water and simmer 3 minutes.

Gradually add milk and heat until hot but do not boil. Using a molinillo (a Mexican chocolate stirrer), a fork, or a rotary beater, whip cocoa until frothy. Pour hot cocoa into mugs or stemmed glasses and serve immediately with dollops of whipped cream and cinnamon sticks.

Variation:

Grate a little nutmeg onto the whipped cream.