Line a baking sheet with parchment paper. In a microwave-safe bowl, heat the white chocolate in 15-second bursts, stirring between each until smooth.
Using a fork, dip an Oreo cookie fully into the melted chocolate. Let the excess drip off. Dip half of the Oreos, then melt the dark chocolate wafers in a separate bowl and repeat the dipping process with the remaining Oreos.
Place the dipped Oreos on the prepared baking sheet immediately after dipping. If you like, sprinkle a few toppings on each cookie while the chocolate is still wet. Let the cookies sit until the chocolate hardens.