Place one of your favourite martini cocktail glasses in refrigerator until chill properly.
Meanwhile, grab a cocktail shaker and fill half of it with crushed ice.
Pour 2 oz of Amber Rum, 0.5 oz of Creme de Cacao, 0.5 oz of Simple Syrup and 0.5 oz of fresh limejuice into the cocktail shaker.
Close the lid of the cocktail shaker thoroughly and shake it vigorously for few seconds until all the ingredients mix well.
Your Ace of Clubs Cocktail is almost ready, strain it into the pre-chilled martini cocktail glass and top it with 4 drops of angostura. Serve immediately.