02Drop batter by rounded tablespoonfuls onto prepared sheets, 2 inches apart. Bake cookies, 1 sheet at a time, until edges are light brown, about 16 minutes. Cool on sheets 5 minutes. Transfer to rack; cool completely.
03Stir chopped milk chocolate in top of double boiler until melted and smooth. Using small spoon, drizzle melted chocolate over cookies in zigzag pattern. Let stand until milk chocolate sets, about 1 hour. (Can be made 2 days ahead. Store in airtight container at room temperature.)