Prep Your Pan: Begin by lining an 8-by-8 inch baking pan with parchment paper. Make sure to leave a convenient one-inch overhang on all sides; this will be your secret weapon for easily lifting out the fudge later!
Boil & Blend: In a medium-sized saucepan, combine the evaporated milk, granulated sugar, and kosher salt. Place it over medium-high heat and bring the mixture to a gentle boil, stirring continuously for exactly 3 minutes. This quick step is essential for the fudge's perfect texture!
Melt & Mix: Immediately take the saucepan off the heat. Quickly stir in the mini marshmallows, bittersweet chocolate chips, and pure peppermint extract. Keep stirring until everything is beautifully melted and wonderfully smooth, creating a velvety chocolate mixture.
Spread the Love: Without delay, pour the warm fudge into your prepared pan. Use a spatula to spread it out evenly, creating a lovely flat layer.
Add Your Topping: Generously sprinkle the crushed peppermints over the fudge. Gently press them down a little to ensure they adhere well. Let the fudge cool slightly at room temperature.
Chill & Set: Transfer the pan to the refrigerator and let it chill for about 1 hour, or until the fudge is perfectly firm and set.
Serve with Style: Once firm, use the parchment paper overhang to effortlessly lift the entire fudge block from the pan. Sprinkle with a delicate pinch of flaky sea salt for an elevated touch, then cut it into delightful bite-sized pieces. Remember to enjoy this sweet treat in moderation! Store any leftover fudge in an airtight container in the refrigerator for up to 3 days. For the best flavor and texture, allow it to come to room temperature for a few minutes before serving.