Begin by combining the white chocolate chips, unsalted butter, vanilla extract, and sweetened condensed milk in a medium-sized mixing bowl.

Melt the mixture in a microwave, starting with intervals of 30 seconds, stirring after each interval. As the mixture begins to melt, reduce the heating time to intervals of 15 seconds, continuing to stir, until a homogeneous consistency is achieved.

Once melted, incorporate the finely chopped pecans into the mixture.

Line a baking dish with parchment paper, ensuring it covers all sides.

Transfer the melted chocolate mixture into the prepared baking dish, spreading it to an even thickness of approximately one inch.

Drizzle the room temperature caramel sauce over the chocolate layer.

Use a knife to create a marbling effect by swirling the caramel into the chocolate, ensuring an even distribution.

Refrigerate the baking dish until the fudge is solid.

Upon solidification, remove the fudge from the refrigerator. Using a sharp knife, cut the fudge into precise one-inch squares for serving.