Combine ingredients and shake without ice: Add the whiskey, lemon juice, and simple syrup to a cocktail shaker, then add the egg white. (I like to break off a small portion of the top of the egg, and then use that as a sort of strainer to hold the yolk in while pouring the white into the shaker.) Shake, without ice, for 60 seconds.

Add ice, shake again, then strain: Add ice to the shaker and shake again for 30 seconds. Strain into a cocktail glass and drop the bitters on the top. Serve!

Alternatively you can reverse dry shake to get extra froff on the top