Prepare all the ingredients and treats you will be dipping in the fondue.

In a small bowl, combine the chocolate, 1/2 cup milk, and butter (if using) and melt gently in a barely simmering water bath or microwave on medium (50 percent) power for about 2 minutes.

Stir until completely smooth. Add more milk if desired.

Remove from heat and stir in the vanilla and salt.

Serve the warm fondue immediately with your chosen dippers.

If the fondue gets too thick, reheat in the microwave in bursts of 15 seconds, stirring between each burst until melted and smooth again.