For the Marshmallows, prepare Red Colored Sugar. Cut marshmallows in half. Dip marshmallows, cut-sides down, in Red Colored Sugar. Set aside.
For the Hot Cocoa, mix milk, sugar, cocoa powder and cinnamon in medium saucepan. Bring to simmer on medium heat, stirring occasionally. (Do not boil.) Remove from heat. Stir in vanilla.
Pour cocoa into mugs. Serve with marshmallows.