In a medium microwave-safe bowl, combine the white chocolate and sweetened condensed milk. Microwave on high for 1 minute, then remove and stir the mixture.

Continue to microwave the mixture in 15-second increments, stirring well after each time, until completely smooth and glossy.

While the chocolate mixture is melting, take a ziplock bag and add the Oreo sandwich cookies. Using a rolling pin, crush the Oreos until they are finely ground.

Once the chocolate mixture is smooth, gently fold the crushed Oreos into it using a spatula.

Line an 8x8-inch baking dish with parchment paper, then pour the Oreo fudge mixture into the lined dish, spreading it evenly.

Refrigerate the fudge for at least 8 hours, or until it is fully set and firm to the touch.

Once set, remove the fudge from the dish using the parchment overhang. Slice it into squares and serve.