01 - In a medium saucepan, combine milk and heavy cream. Heat on medium until steaming without boiling.
02 - Add chopped dark chocolate and chocolate hazelnut spread. Whisk until fully melted and smooth.
03 - Taste the mixture and add granulated sugar if desired. Whisk until dissolved.
04 - Continue heating for 2 to 3 minutes, stirring frequently, until the beverage is rich and creamy.
05 - Pour into mugs and top with whipped cream, toasted hazelnuts, and chocolate shavings as preferred. Serve immediately.