01 - Line an 8x8-inch baking pan with parchment paper, leaving an overhang for easy removal.
02 - In a medium saucepan over low heat, combine white chocolate chips, sweetened condensed milk, and unsalted butter. Stir constantly until the mixture melts and becomes smooth.
03 - Remove the saucepan from heat. Stir in the vanilla extract and a pinch of salt until evenly incorporated.
04 - Evenly divide the melted mixture into three separate heatproof bowls.
05 - Leave one bowl plain for the white layer. Add orange gel food coloring to the second bowl and stir until evenly tinted. Add yellow gel food coloring to the third bowl and mix well.
06 - Working quickly, spread the yellow fudge mixture evenly in the bottom of the prepared pan. Layer the orange mixture on top of the yellow, followed by the white mixture. Use a skewer or butter knife to gently swirl the layers for a marbled effect without overmixing.
07 - If desired, sprinkle chopped candy corn on top and gently press into the surface.
08 - Refrigerate the pan for at least 2 hours, or until the fudge is completely set.
09 - Using the parchment overhang, lift the fudge from the pan and place on a cutting board. Cut into 36 squares and serve.