You'll need a proper glass, of course.
Whip heavy whipping cream to a thick froth that stands. Toss 1 tsp. table sugar in the bottom of a proper Irish whiskey glass. Add 1 oz. Irish whiskey. I like Jameson, but Irish whiskey and coffee is an alchemy of sorts. You'll have to find your own right mix. Fill that glass to within 1/2-inch of the top with fresh-brewed black coffee. I like Peet's. Regardless, use a full-flavored coffee, but not too roasted. Alchemy, remember? Add 1/8-tsp. of vanilla extract to the coffee. Spoon whipping cream on the top so that it makes a nice mound. Watch the lovely strands of cream make fractal curlicues down the glass. Drink. Repeat.