01 - Line an 8 x 8 inch square baking pan with parchment paper, leaving an overhang for easy removal.
02 - Over low heat, combine chopped white chocolate, sweetened condensed milk, and cubed butter in a medium saucepan. Stir continuously until fully melted and smooth.
03 - Remove saucepan from heat. Stir in peppermint extract and a pinch of sea salt until evenly incorporated.
04 - Transfer the mixture into the prepared pan, smoothing the surface with a spatula.
05 - Evenly sprinkle crushed peppermint candies over the top and gently press into the mixture.
06 - Allow to cool at room temperature for 10 minutes, then refrigerate for at least 2 hours or until set.
07 - Lift fudge from pan using parchment overhang, cut into 36 squares, and serve.