Heat your glass with hot water for 10-15 seconds; dump the water.
Build the cocktail into a coffee cocktail mug, and stir until mixed together.
Whisk up heavy whipping cream in your cocktail shaker with a whisk or the coil on your Hawthorne strainer; shake (or whisk) the cream in shaker with the coil.
Use a bar spoon to float the freshly-whipped cream on top of the cocktail.