Lightly mist a 8x8-inch pan with non-stick spray, and line it with parchment.

Place the chocolate, condensed milk, and salt in a large bowl over very low heat.

Stir the mixture continuously, until all the chocolate has melted and the mixture is very thick and shiny.

Remove from the heat and stir in the vanilla extract.

Transfer the fudge to the prepared pan, smoothing it into an even layer.

Allow it to cool and set (about 1 hour), before cutting into 24 squares.