2 cups heavy cream
2-4 small dried red chiles, seeds removed, broken into ½-inch pieces
5 ounces bittersweet chocolate, finely chopped
5½ ounces Mexican chocolate (see note below)
1 teaspoon cinnamon
1¾ cups granulated sugar
½ cup Lyle's Golden Syrup (light corn syrup can be substituted)
¼ cup water
¼ teaspoon table salt
3 tablespoons unsalted butter, cut into cubes
2 teaspoons fleur de sel, or other type of flaky sea salt
1. Line an 8-inch-square baking pan with two perpendicular pieces of parchment paper, so that there is overhang on all four sides. Set aside.
2. In a small saucepan over medium-high heat, bring the cream to a boil. As soon as it reaches a boil, add the chile pieces, give it a quick stir, remove from heat, and cover. Allow the chiles to steep in the cream for at least 30 minutes. Remove the chile pieces with a slotted spoon and discard.
3. Return the strained cream to a boil over medium-high heat, then reduce the heat to low, add both chocolates and the cinnamon. Let stand for 1 minute, then stir until chocolate is completely melted. Remove from heat and set aside.
4. Bring the sugar, syrup, water, and table salt to a boil in a 5 to 6-quart heavy pot over medium heat, stirring until the sugar has dissolved. Boil, uncovered, without stirring but gently swirling the pot occasionally, until the sugar is a deep golden color, about 10 minutes.
5. Tilt the pot slightly and carefully pour the chocolate mixture into the sugar mixture (it will bubble and steam quite a bit). Continue to boil over medium heat, stirring frequently, until the mixture reaches 255 degrees F.
6. Add the butter, stirring until it has completely melted, then immediately pour the caramel mixture into the lined baking pan (do not scrape any caramel clinging to the bottom or side of the pot, as these pieces will have crystallized). Let the caramel stand for 10 minutes, then sprinkle evenly with the fleur de sel. Allow to cool completely in the pan on a wire rack, about 2 hours.
7. Using the parchment overhangs as handles, carefully lift the caramel onto a clean, dry cutting board. Spray a pizza cutter or large knife with non-stick cooking spray and slice the caramel into 1-inch squares. Wrap the candies individually and store in an airtight container for up to 1 month.
Note: Common brands of Mexican chocolate are Ibarra, Abuelita, and Taza. I found Abuelita in the Hispanic section of the international aisle in my local supermarket; you can also find all three brands online. If you want to make these and can't get Mexican chocolate easily, you can use this substitution: