Coat an 8x8x2-inch square pan with cooking spray, and line with parchment.

Melt chocolate in a double boiler or a heatproof bowl set over a pan of simmering water, stirring until melted.

Pour chocolate into the prepared pan, and spread in an even layer. Seed the top with chopped cookies, gently pressing them into the white chocolate. Refrigerate until firm, about 1 hour. Break into pieces.