Start by lining a 9-inch square baking pan with parchment paper. This step is essential to ensure your fudge comes out easily once it’s set.
In a medium saucepan over low heat, combine the chopped semi-sweet chocolate and the butter. Stir continuously until both are melted and smooth. Be sure to keep the heat low to prevent the chocolate from seizing.
Once the chocolate and butter are melted, remove the saucepan from heat. Stir in the sweetened condensed milk and vanilla extract. Mix until the ingredients are well combined and the mixture is silky.
Pour the chocolate mixture into the prepared baking pan, spreading it evenly. If you’re using nuts or candies, sprinkle them on top at this point, pressing them into the fudge slightly. Optionally, sprinkle flaky sea salt for an added touch of flavor.
Refrigerate the fudge for at least 2 hours or until firm. The longer you let it chill, the easier it will be to cut into squares.
Once set, lift the fudge out of the pan using the parchment paper. Use a sharp knife to cut it into squares. Enjoy your Foolproof Chocolate Fudge as is, or package it up for sharing!
