Warm an Irish whiskey glass by filling it with hot water.
Pour out the water and add hot coffee to the glass.
Add the whiskey and the brown sugar and stir to combine.
Top with whipped cream.
Video
Notes
Whipped cream - you want to use real whipped cream. Whip it by hand with a whisk so that you can stop just as it reaches the whipped stage. You want to still be able to pour it, not dollop it on.