Mexican Hot Chocolate

Method

1. infuse5 min
   milk + cinnamon stick, low, below a simmer
   the milk warmed with the cinnamon stick until it steams — never boiled: boiled milk skins and scorches, and every step after this happens below that line; the stick infuses rounder than ground cinnamon and leaves no grit
2. whisk5 min
   chocolate in, melted completely
   the chopped tablet whisked into the hot milk until dissolved + salt + vanilla — tablet chocolate is coarse with cane sugar and almond by design, and the slight granular texture in the finished cup is authentic, not a failure to melt; the scratch fallback (cocoa + brown sugar + a pinch more cinnamon) makes a smoother, darker cup
3. whisk2 min
   the froth — hard, off heat
   whipped vigorously until a head of foam stands — a molinillo spun between the palms if the kitchen owns one, a whisk or thirty seconds of blender if not — the froth is canonical: the drink is judged by its foam collar, and pouring from height between two pots is the grandmother's method. Cayenne on top for those who take it