1. Line an 8×8 inch baking pan with parchment paper, leaving an overhang on the sides for easy removal.

 

 

2. In a medium saucepan, combine the semi-sweet chocolate chips, sweetened condensed milk, and butter over low heat. Stir until melted and smooth.

 

 

3. Remove from heat and stir in the vanilla extract.

 

 

4. Fold in the mini marshmallows until evenly distributed.

 

 

5. Pour the fudge mixture into the prepared baking pan and spread it into an even layer.

 

 

6. In a small microwave-safe bowl, melt the white chocolate chips in 30-second intervals, stirring until smooth.

 

 

7. Drizzle the melted white chocolate over the fudge mixture.

 

 

8. Use a toothpick or knife to swirl the white chocolate into the fudge to create a marbled effect.

 

 

9. Refrigerate the fudge for at least 2 hours, or until set.

 

 

10. Once set, lift the fudge out of the pan using the parchment paper overhang and cut into squares.