Preparation Steps

• In a medium saucepan over medium heat, combine heavy cream, corn syrup, and brown sugar. Cook, stirring often, until the sugar dissolves and the mixture is steaming.
• Whisk in the cocoa powder until fully smooth and no dry streaks remain. Bring to a gentle simmer (do not boil) and cook for 3 to 4 minutes, whisking, until glossy and slightly thickened.
• Remove from heat. Add the chopped semisweet chocolate and butter. Let sit for 1 minute, then whisk until completely melted and silky.
• Whisk in vanilla, fine sea salt, and espresso powder (if using). Taste and adjust salt to preference.
• Return the pan to low heat and cook for 2 to 3 minutes more, stirring, until the sauce coats the back of a spoon. The sauce will thicken further as it cools.
• Serve warm over ice cream, brownies, or fruit. Finish with a pinch of flaky sea salt just before serving.
• Store leftovers in a sealed jar in the refrigerator for up to 2 weeks. Rewarm gently in the microwave or over low heat, stirring often.