This is a classic, hot coffee drink done right, with a special trick for whipping cream. The details make it great: the combination of fresh-brewed hot coffee, a good Irish whiskey, and freshly whipped cream is hard to resist.
Measure heavy cream and 1/4 oz simple syrup into a cocktail shaker (simple syrup is equal parts sugar and water, brought to a boil and cooled). Remove the spring from the cocktail strainer and add into the shaker. Shake as a cocktail for approximately one minute, until the cream has been whipped. For the coffee: Combine whiskey, 1/2 oz simple syrup, and coffee in the serving glass. Top with a few dollops of whipped cream.