Melt all the ingredients, except the essential oils, in a double boiler. You can make your own double boiler by placing a glass bowl over a medium-size saucepan.

Bring the water to a boil until the ingredients are melted. Once ingredients are melted, remove the bowl from the heat.

Let mixture cool slightly, and then add in essential oils. Stir well until combined.

Pour the mixture into silicone molds or metal tins.

Allow the mixture to cool completely, and then pop the bars out of the molds.

Store in an airtight container for up to one year.