Preheat mug or heatproof glass by filling with hot water. Allow it to warm, then discard the water.
Fill mug with hot coffee, add the caramel sauce and brown sugar and stir until dissolved.
Add whiskey and stir to incorporate.
Top with whipped cream. If cream is lightly whipped, pour it gently over a spoon into the coffee. To make higher peaks, whip the cream to medium peaks and then dollop it on top.