Prepare Your Pan: Line an 8x8-inch baking pan with aluminum foil or parchment paper, leaving some overhang on the sides for easy removal. Set aside.

Melt the Ingredients: In a medium saucepan over medium heat, combine the white chocolate chips, sweetened condensed milk, and butter. Stir continuously until the white chocolate chips are fully melted and the mixture is smooth.

Pour and Set: Remove the mixture from heat and pour it into the prepared pan, spreading it evenly with a spatula.

Chill: Refrigerate the fudge for at least 3 hours, or until it is completely firm.

Cut and Serve: Once set, use the overhang to lift the fudge out of the pan. Cut into small squares and enjoy!