Line an 8-inch square baking dish with parchment paper, leaving some overhang for easy removal later.

In a medium saucepan, combine the white chocolate chips and sweetened condensed milk over low heat. Stir gently until smooth.

Remove from heat and stir in chopped maraschino cherries, vanilla extract, and salt. Optionally, mix in cocoa powder for a swirl effect.

Pour the mixture into the prepared pan, spreading it evenly with a spatula. Optionally arrange whole cherries on top.

Chill in the fridge for at least 2 hours or until set.

Lift the fudge out of the pan using the parchment overhang and slice into squares to serve.