Preparation Steps

• Line a 9-inch square pan with parchment so it overhangs two sides for easy lifting; lightly butter the exposed parchment and corners.
• Place the chopped dark chocolate in a large heatproof bowl. Add the vanilla, fine sea salt, and espresso powder on top (do not mix yet).
• In a heavy 3-quart saucepan, combine sugar, evaporated milk, and butter. Warm over medium heat, stirring until the sugar dissolves and the butter melts, 3–4 minutes.
• Bring the mixture to a steady boil over medium heat. Clip on a candy thermometer and cook, stirring occasionally, until it reaches 235–238°F (soft-ball stage), 5–6 minutes.
• Immediately pour the hot syrup over the chocolate mixture. Let it sit undisturbed for 2 minutes, then stir from the center outward until completely smooth and glossy. If a few bits remain, set the bowl over a pan of hot (not simmering) water and stir just until melted.
• Beat the fudge by hand with a spatula for 45–60 seconds until it thickens slightly and loses a little shine—this helps the texture set finely.
• Scrape into the prepared pan, tap firmly on the counter to release bubbles, and smooth the top. Sprinkle a pinch of flaky sea salt if using.
• Let set at cool room temperature until firm, 2–3 hours, or refrigerate 45–60 minutes. Lift out by the parchment, trim edges if desired, and cut into 36 small squares, wiping the knife between cuts.