Add the Oreo cookies to a blender or food processor and blend until the mixture resembles crumbs.
Transfer the mixture to a mixing bowl (or to the bowl of a stand mixer) and add the cream cheese and powdered sugar, mixing on low speed just until the mixture comes together evenly.
Cover the bowl with plastic wrap and refrigerate for 2-3 hours so the mixture will firm up. Alternatively, place in the freezer for about 30-45 minutes to chill.
Once the mixture has chilled, roll into balls and dip in melted semi-sweet chocolate, placing them on a parchment-lined baking sheet so the chocolate can harden. You can melt the chocolate on 50% power in the microwave for 30-second increments, stirring regularly until the chocolate is melted.
Drizzle with the melted white chocolate and refrigerate until the chocolate has set (about 25 minutes).
Serve on a holiday cookie tray with all your other favourite treats, or give as edible holiday gifts!
Notes
Store in the fridge for up to 4 days until you're ready to serve, and freeze for up to 3 months if you wish!