Line a baking sheet with parchment paper; set aside.
Place the chopped chocolate in a medium bowl and either melt over a double boiler or melt in the microwave on 50% power in 30-second increments, stirring after each.
Once the chocolate is melted, pour it onto the parchment-lined sheet and spread it into a roughly 9-inch square. Sprinkle the chopped Oreos on top of the chocolate and gently press them into the chocolate. Refrigerate until set, about 30 minutes. The bark can be kept in an airtight container in the refrigerator for up to 2 weeks.