1Heat oven to 375°F. Line cookie sheet with cooking parchment paper.
2In large bowl, mix all cookie ingredients with electric mixer on medium speed until well blended. Onto cookie sheet, drop dough by rounded teaspoonfuls.
3Bake 9 to 11 minutes or just until edges begin to brown. Cool 1 minute; remove from cookie sheet to cooling rack. Cool completely, about 20 minutes.
4In medium bowl, mix 1/4 cup butter, the powdered sugar and 3 tablespoons lemonade concentrate with electric mixer on low speed until smooth. Add remaining 1 tablespoon concentrate, 1 teaspoon at a time, if needed for desired consistency. Frost cookies.