Instructions
Layer Amaretto and rum in a shot glass in that order. Fill a beer mug halfway with the beer. Light the rum, let it burn for a bit, then dunk the shot glass in the beer and chug.
Notes
If you have trouble lighting the rum, you can try warming the shot glass before you use it. Just put it in a microwave for a 10-15 seconds. Make sure the Amaretto and rum are room temperature.
Be very careful when you light the rum. It is best to use a long match.