Step 1

Spread out the black sugar on a small plate. Rub the lime wedge around the rim of a rocks glass; dip the glass in the black sugar, then fill with ice.

Step 2

Combine the rum and lime juice in a cocktail shaker. Fill with ice and shake well. Carefully strain into the glass, minding the sugar on the rim. Top the drink with ginger beer and add the gummy spider.