Hot Fudge Sauce

In a medium-sized sauce pan, mix together heavy cream, corn syrup, sugar, cocoa, salt, espresso, and half of the dark chocolate chips. Bring to a low boil over medium heat, stirring constantly. Once boiling, boil lightly for 5 minutes, stirring constantly, then remove from heat.

Whisk in butter, vanilla, and remaining chocolate chips. Stir until smooth.

Let cool slightly before serving. If serving later, transfer to a covered container, and let cool completely before refrigerating. Reheat before using.

Sauce can be kept in the fridge for 1 week.