This hot fudge has a butter caramel base, giving it a magical texture that's molten when hot and pleasantly chewy where it touches a cold scoop of ice cream. This gives the hot fudge some substance, and yet it melts away into a blissful pool of buttery chocolatey caramel in your mouth.
Add the 2 tablespoons water and ¼ cup light corn syrup to a heavy bottomed pot and bring to a boil. Dump the ½ cup evaporated cane sugar into center of the pot in a mound making sure you don't get any sugar on the sides of the pot.
2 tablespoons water, ¼ cup light corn syrup, ½ cup evaporated cane sugar
Let this mixture boil until until it reaches 320 degrees F (160 C).
Add the ⅔ cup heavy cream a little bit a time, whisking well to incorporate. If you add too much cream at once, it will boil over.
⅔ cup heavy cream
Whisk in the 2 tablespoons cultured unsalted butter and 3 tablespoons cocoa powder and then whisk in the 120 grams bittersweet chocolate, a little bit at a time. Finish the hot fudge by whisking in the 1 teaspoon vanilla extract and 1 pinch sea salt