Meanwhile, in small bowl, stir remaining cooled butter, powdered sugar and half-and-half until smooth, if necessary, adding 1/2 teaspoon half-and-half at a time until thin enough to drizzle. Pour into 1-quart resealable food-storage plastic bag. Cut off small corner of bag. Pipe onto cookies. Let stand about 1 hour or until drizzle is set. Store in airtight container.