Add half and half, cocoa powder, sugar, and cinnamon to a medium pot over medium-low heat. Whisk together frequently until the mixture heats up and starts to steam.
Pour the chocolate mixture into a milk frothing pitcher and froth with a frothing wand.
Add the brewed espresso to a mug. Pour the frothed chocolate mixture on top. Top with whipped cream, chocolate shavings, and chocolate sundae syrup, if desired. Serve hot.