Line a large baking sheet with parchment paper or a silicone baking mat. Set aside.

Place white chocolate in a microwave-safe bowl. Microwave in 30-second intervals, stirring between each, until about 90% melted. Remove from microwave and stir until completely smooth, letting residual heat melt any remaining pieces.

Crush Oreo cookies by placing them in a sealed plastic bag and gently smashing with a rolling pin or the bottom of a measuring cup. Aim for a mix of small crumbs and larger chunks.

Reserve about 1/4 cup of crushed Oreos for topping. Fold the remaining crushed cookies into the melted white chocolate until evenly distributed.

Pour the chocolate mixture onto the prepared baking sheet. Use a spatula to spread into an even layer about 1/4-inch thick, creating any shape you like.

Sprinkle the reserved crushed Oreos over the top, pressing gently to help them adhere. Sprinkle with flaky sea salt if desired.

Refrigerate for at least 1 hour or until completely firm and set.

Once hardened, break the bark into irregular pieces using your hands or cut into squares with a sharp knife. Store in an airtight container in the refrigerator.