Black Widow Martini Recipe... Ingredients 1 1/2 oz black rum 3/4 oz crème de cacao 1 cup ice Black food color 1 tablespoon brown sugar 1: Add black rum, crème de cacao, ice and 1 or 2 drops black food color to a martini shaker. 2: In small bowl, add brown sugar and 1 drop black food color. Mix with fork until all sugar is black. Wet rim of martini glass with water. Dip rim into sugar. 3: Strain martini into glass, and serve.