Remove 2 tablespoons lemonade concentrate from can, and reserve for another use.
Combine remaining concentrate, cake mix, and next 3 ingredients in a mixing bowl. Beat at low speed with an electric mixer until moistened. Beat at high speed 3 minutes, stopping to scrape down sides. Spoon batter into 30 paper-lined muffin cups, filling each three-fourths full.
Bake at 350° for 22 minutes or until a wooden pick inserted in center comes out clean. Cool in pans on a wire rack 5 minutes. Remove cupcakes from pans; cool completely on wire rack. Spread evenly with frosting. Garnish, if desired.