In a double boiler over medium heat, place chopped white chocolate. Heat until chocolate is melted and stir in cayenne pepper and cinnamon. Add beaten egg and whisk until smooth. Gradually add 1 cup milk and heat, whisking constantly, for 2 minutes. Gradually add remaining 2 1/4 cups milk and stir until heated throughout. Make sure not to let mixture simmer or boil to avoid a skin from forming on top milk. Pour hot mixture into four coffee mugs. If desired, garnish with additional cinnamon on top.