In a medium saucepan, combine 2-3 cups of whole milk and ½ cup of heavy cream. Heat the mixture over medium heat until it begins to steam, stirring occasionally.

While the milk is heating, whisk together ½ cup of cocoa powder and 1-2 tablespoons of grated milk chocolate in a separate bowl. Slowly add ½ cup of the heated milk mixture to the cocoa mixture, whisking vigorously until smooth.

Pour the chocolate mixture back into the saucepan with the remaining milk and cream while whisking continuously. Stir in the entire can of sweetened condensed milk and ⅛ teaspoon of vanilla extract.

Reduce the heat to low and let the hot chocolate simmer for 3-5 minutes, stirring frequently until it thickens slightly.

Pour the hot chocolate into mugs. Top with whipped cream and ground cinnamon and serve immediately.