In a rocks glass with a single ice cube, combine the sugar cube/granulated sugar and Angostura Bitters.

Stir the mixture until the ice cube has melted enough to dissolve the sugar - if using a sugar cube, crush it first.

Stir in 3 to 4 more ice cubes and half of the Bacardi Dark rum for about 60 seconds.

Add more ice to the glass and the remaining Bacardi Dark rum, then stir for another 60 seconds.

Cut an orange peel into a piece the size of your thumb (be careful not to bend it yet). Bend the orange peel over the glass to release some of the oil into the drink.

Add the orange peel to the drink, stir a few times more, and serve. The wait is well worth it.