Melted running dark chocolate swirl with a piece of chocolate bar inside background - Shulevskyy Volodymyr/Shutterstock If you don't have the tools for a double boiler or want a quicker option ...

Melting chocolate and butter in a pot on the stove - Ugis Bralens/Shutterstock A double boiler is one of those pieces of specialty kitchen equipment that does one job and does it very well.