Following the manufacturer’s directions, melt the soap base on low-medium heat. Once melted, add brown sugar. Turn off heat to prevent boiling; stir with a chopstick. Add drops of essential oil. Stir until completely incorporated. 

Pour mixture into the mold.  Tap mold to remove any air bubbles. Let cool and harden at room temperature, or place in the refrigerator. 

Package soaps for gift giving, as desired.