If you can't find blanched hazelnuts, toast 1/2 cup hazelnuts at 350°F about 10 minutes or until skins begin to crack. Remove from oven; cool slightly. Rub hazelnuts vigorously in a clean towel to remove as much of the skin as you can.
Layer cookies between sheets of waxed paper in an airtight container; cover. Store at room temperature for up to 3 days or freeze for up to 3 months.