Combine ingredients in a shaker with ice and shake. Strain into a glass filled with ice and top with more ice. Add garnish.

GARNISH INSTRUCTIONS:
Use a knife or spoon to remove the flesh from a halved lime, forming a bowl shape. Soak a sugar cube with 151-proof rum and add it to the lime shell. Place the shell on pebble ice or crushed ice for stability, and top with another splash of high-proof rum. Light with a long match then sprinkle ground cinnamon over the flame for dramatic sparks.

But most importantly, proceed with all the caution.