Add chocolate chips, sweetened condensed milk, and salt to a medium heavy-bottomed saucepan over medium-low heat. Melt the chocolate, stirring frequently. Remove from heat and stir in vanilla extract. Fold in chopped peppermint bark.
Pour into prepared dish and spread with an offset spatula. Sprinkle with crushed peppermint candy. Cover with plastic wrap and refrigerate for 2 hours to set. Remove from refrigerator and remove from baking dish. Cut into 24 or 48 individual squares with a sharp knife.
Store in layers with wax paper or parchment dividing in an airtight container on the counter for up to 7 days or in the refrigerator for 2 to 3 weeks.
Notes
Storage Tips
Fudge is best stored at room temperature in an airtight container for 2 to 3 weeks. Do not store fudge in the refrigerator as it will cause the fudge to become dry and crumbly.