In the bowl of your mixer, beat cream cheese, sugar, and vanilla until smooth and no lumps remain.
In the top of a double boiler (or just a glass bowl set over a pot) over lightly simmering water, heat white chocolate, stirring until melted and smooth.
Stir the melted white chocolate and 3/4 of the Oreo cookies into the cream cheese mixture.
Spread into a parchment lined 8x8 baking dish. Press the remaining cookies into the top of the fudge to make it look pretty.
Chill in the fridge for at least 4 hours before cutting.
Cut into 1-inch squares (or smaller - this stuff is rich!) and serve!