From the Washington Post
Ingredients
2 ounces whiskey
1 egg white (optional)
1 ounce freshly-squeezed lemon juice (or other citrus juice)
3/4 ounce maple syrup
2–3 shakes Angostura bitters (optional)
ice
Instructions
1. If using the egg white, add whiskey and egg white to a cocktail shaker and vigorously shake for 15-20 seconds until the egg white is very frothy. (If not using the egg white, you can skip this step.)
2. Add the lemon juice, maple syrup, bitters (if using) and a handful of ice to the shaker, and shake for a few seconds to combine and chill the drink. Strain and serve immediately in a glass over ice.