01 -
Butter an 20 cm x 20 cm baking pan and line it with parchment paper, leaving a 5 cm overhang on two opposite sides. In a medium saucepan over medium heat, combine butter, dark chocolate chips, sweetened condensed milk, vanilla extract, and kosher salt. Stir constantly with a rubber spatula until the chocolate has melted completely and the mixture is smooth, approximately 5 minutes. Pour the mixture evenly into the prepared pan.
02 -
Sprinkle the Christmas decorations evenly over the chocolate mixture. Place the pan in the refrigerator and chill until fully set, for a minimum of 2 hours and up to 24 hours.
03 -
Run a sharp knife around the edges of the pan to loosen the fudge. Using the parchment overhang, carefully lift the fudge out and transfer it onto a cutting board. If the fudge resists removal, wait 5 minutes at room temperature before trying again. Cut the fudge into approximately 3.8 cm squares for serving.