•6 oz2/3 cup fine-quality bittersweet chocolate chips
•2 tablespoons unsalted butter
•1 teaspoon vanilla
Bring cream, corn syrup, sugar, cocoa, salt, and half of chocolate to a boil in a 1 to 1 1/2-quart heavy saucepan over moderate heat, stirring, until chocolate is melted. Reduce heat and cook at a low boil, stirring occasionally, 5 minutes, then remove from heat. Add butter, vanilla, and remaining chocolate and stir until smooth. Cool sauce to warm before serving.
Can be made a week ahead of time. I stored mine in a glass jars (two 8 ounce jars) and kept in the fridge. Just reheat before serving.
Adapted from Epicurious