1. Mix together cocoa powder, sugar and salt in 3-quart saucepan.
2. Pour in milk, whisking until smooth. Heat over medium-high heat until dissolved, about 5 minutes.
3. Stir in light cream and vanilla, and cinnamon if desired. Heat to just under boiling over medium-high heat, 7 to 10 minutes, whisking.
4. Mix well and divide into 6 mugs. Top with whipped cream, orange rind and cocoa powder, if desired.