Make the espresso: Make the espresso using an espresso machine, manual espresso maker, French press, or Moka Pot. Go to How to Make Espresso for instructions.
Shake: Place the hot espresso and chocolate chips in a covered jar: vigorously shake until melted. Pour into an ice filled glass.
Froth the milk: Rinse out the jar. Place the milk and simple syrup back into the jar, cover and shake until foamy.
Serve: Top the chocolate espresso with the frothed milk. Enjoy immediately.